Namtok Phlio National Park

Nature and Royal History in One Landscape

Hidden in the green mountains of eastern Thailand, Namtok Phlio National Park protects a compact but remarkably diverse landscape of rainforest, mountain streams, waterfalls and historical monuments.

Its best-known attraction is Phlio Waterfall, where clear mountain water pours into a natural pool inhabited by large schools of stone-sucking carp, known locally as pla phluang hin.

But there is another layer. In the nineteenth century, King Chulalongkorn, Rama V, visited the waterfall with Queen Sunandha Kumariratana and became deeply impressed by its scenery. A laterite chedi still stands near the falls. Nearby, a pyramid-shaped memorial preserves the memory of Queen Sunandha.

You can walk through rainforest, stand beside a waterfall, watch fish moving through crystal-clear water, and then encounter nineteenth-century monuments within minutes. That combination is what makes Namtok Phlio special.

Nature and royal history occupy the same landscape.

At a Glance

11th

National park of Thailand. Established 2 May 1975 as Khao Sa Bap; renamed 1982.

134.50 km²

Approximately 84,062.5 rai across the Khao Sa Bap mountains.

Phlio Falls

Clear pools, rainforest and schools of stone-sucking carp.

Royal story

Alongkorn Chedi (1876) and Sunandha Memorial Pyramid (1881).

Official English name

Namtok Phlio National Park

Thai name

อุทยานแห่งชาติน้ำตกพลิ้ว

Province

Chanthaburi

Districts covered

Mueang Chanthaburi, Laem Sing, Khlung and Makham

Area

Approximately 134.50 km² / 84,062.5 rai

Mountain range

Khao Sa Bap Range

Elevation

Approximately 20–924 m above sea level

Highest point

Map Wa Krok / Maph Wā Krok area, approximately 924 m

National park status

Established 2 May 1975 · 11th national park of Thailand

Original name

Khao Sa Bap National Park

Name change

29 September 1982 → Namtok Phlio National Park

Signature attraction

Phlio Waterfall

Wildlife highlight

Stone-sucking carp / Soro brook carp (pla phluang hin)

Historical highlights

Alongkorn Chedi · Sunandha Memorial Pyramid

Other waterfalls

Khlong Narai, Trok Nong, Makok and smaller cascades

Other attractions

Huai Ta Bo Reservoir, forest trails and streams

DNP’s current national-park information confirms that Namtok Phlio covers parts of Mueang Chanthaburi, Laem Sing, Khlung and Makham districts. The commonly cited park area is approximately 134.50 square kilometres, or about 84,062.5 rai.

Where Is Namtok Phlio?

Namtok Phlio National Park is located in Chanthaburi Province in eastern Thailand. The principal waterfall area lies in Phlio Subdistrict, Laem Sing District, approximately 14–15 kilometres from Chanthaburi city.

The park extends beyond the immediate waterfall area into a larger mountainous landscape covering parts of Mueang Chanthaburi, Laem Sing, Khlung and Makham. The waterfall most visitors see represents only a small, accessible portion of the protected landscape. The surrounding mountains contain forests, streams and additional waterfalls that require more time to explore.

TAT identifies Phlio Waterfall as one of Chanthaburi’s major natural attractions and places it among the province’s principal destinations.

The Khao Sa Bap Mountains

The park is centred on the Khao Sa Bap mountain range. This is an important detail because Namtok Phlio is not simply a waterfall surrounded by trees — it is a mountain watershed.

The terrain rises from approximately 20 metres above sea level to around 924 metres at its highest point. Elevation changes create different forest conditions and allow numerous streams to descend from the mountains. The highest point traditionally identified within the park is the Map Wa Krok area, approximately 924 metres above sea level.

The Story of Phlio Waterfall

The waterfall that became a destination

Phlio Waterfall is the heart of the national park. It is not an enormous vertical waterfall. Instead, its appeal comes from the combination of clear water + rock + rainforest + fish + accessibility.

The waterfall is formed by mountain streams descending over rock before collecting in clear natural pools. The water continues through the forest downstream. TAT describes Phlio as a three-level waterfall with a clear pool and identifies the fish-filled stream as one of its distinctive attractions.

The water is not simply rushing past you. It is transparent.

Clear Water, Living Water

One of the first things visitors notice is the clarity of the water. The natural pools are sufficiently clear that the rocky and sandy bottom can often be seen beneath the surface.

This clarity is one of the reasons Phlio Waterfall has become famous for its fish. It also creates a visual effect that makes the waterfall feel calmer than many larger Thai waterfalls. You can see the landscape continuing beneath the surface.

The Stone-Sucking Carp

The fish that made Phlio famous

One of Namtok Phlio’s most distinctive natural features is its population of large freshwater fish. They are commonly known in Thai as Pla Phluang Hin — ปลาพลวงหิน and are generally referred to in English as stone-sucking carp or Soro brook carp.

The fish belong to the mahseer group of freshwater cyprinids. They live in clear mountain streams and pools, particularly around rocky riverbeds. At Phlio Waterfall, large numbers can gather in the clear water. DNP has described the waterfall as having streams filled with tens of thousands of stone-sucking carp, highlighting them as one of the site’s defining natural features.

Why are there so many fish?

• Clear flowing water
• Rocky riverbeds and pools
• Forest shade
• Continuous water flow
• Natural food sources

The forest surrounding the stream helps maintain water quality by protecting the watershed. The fish are not a separate attraction — they are part of the river ecosystem.

A Rainforest Waterfall

The waterfall is surrounded by humid forest. Trees provide shade along the stream, creating a cooler microclimate than the open agricultural and urban areas outside the park. The forest also helps regulate water — rainfall is absorbed into the mountain environment before emerging through streams and flowing toward the falls.

Forest → water → waterfall → fish

Namtok Phlio contains humid tropical forest environments associated with the Khao Sa Bap mountains. Botanical surveys have recorded dipterocarps, evergreen forest trees, fruiting trees, vines, ferns and other tropical vegetation. Vegetation varies with elevation and moisture: lower visitor areas are relatively accessible; higher mountain areas become increasingly forested and rugged.

Biodiversity Beyond the Waterfall

Namtok Phlio’s forests form part of the Thai portion of the Cardamom Mountains landscape, with the Khao Sa Bap massif representing an isolated western extension associated with the larger Cardamom system.

A scientific study of reptiles in the park noted that Namtok Phlio preserves an isolated forest fragment associated with the Cardamom Mountains and documented the Annam kukri snake (Oligodon annamensis) in the park — a significant extension of the known distribution of that species in Thailand.

The park is therefore more than a recreational waterfall. It is also a small but biologically important forest island.

Birds & Forest Wildlife

Visitors who spend time away from the busiest waterfall area may encounter a variety of forest birds and smaller wildlife. Historical records and field observations associated with the Khao Sa Bap landscape include species such as:

• Siamese fireback
• Silver pheasant
• Chestnut-headed partridge
• Blue-rumped pitta
• Various babblers, barbets, sunbirds and forest flycatchers

These species should not be interpreted as guaranteed sightings. Bird populations move according to season, food availability, weather and disturbance. The best approach is to enter the forest quietly and allow wildlife to appear naturally.

The Royal Connection

When nature became part of history

Namtok Phlio is unusual among Thai national parks because its landscape is closely associated with the history of King Chulalongkorn, Rama V, and Queen Sunandha Kumariratana.

Historical sources agree that the royal couple visited Phlio Waterfall during the 1870s and that the King was deeply impressed by the landscape. There is, however, a discrepancy among official sources concerning the exact year of the first visit:

• DNP’s 2026 historical account gives B.E. 2416 / 1873.
• ONEP’s cultural-heritage record and TAT’s English material give B.E. 2417 / 1874.

For historical accuracy, ThailandLover avoids presenting one of these conflicting dates as uncontested fact.

A surviving account records Rama V’s comparison of Phlio with other waterfalls he had visited, including Penang, Ko Chang and Si Phaya — essentially that he had not seen another waterfall more beautiful than Phlio, and that he could happily sit there until evening because of the cool and refreshing atmosphere. The waterfall was not merely visited. It was remembered.

Alongkorn Chedi

A monument beside the waterfall · 1876

Alongkorn Chedi was constructed from laterite in 1876. It commemorates the royal visit to Phlio Waterfall. The monument stands on elevated ground close to the waterfall and remains surrounded by forest. Over time, the humid environment has covered portions of the laterite surface with moss and vegetation.

A nineteenth-century monument embedded within a living rainforest.

The chedi is not simply an old monument. It provides physical evidence of the historical relationship between the royal court and the landscape. Today, visitors can experience both the natural landscape and the historical structure within the same short walk. That is rare.

Sunandha Memorial Pyramid

Phra Nang Ruea Lom Pyramid · 1881

A short distance from the waterfall stands another remarkable structure: the Sunandha Memorial, also commonly called Phra Nang Ruea Lom Pyramid or Pyramid of Phra Nang Ruea Lom.

It is a pyramid-shaped memorial constructed in 1881, during the reign of Rama V. The monument commemorates Queen Sunandha Kumariratana, who died in a royal barge accident on the Chao Phraya River. Part of her ashes was placed within the memorial.

Why a pyramid?

According to the historical account preserved by ONEP and DNP, Rama V wanted the memorial to endure in a remote forest environment. The pyramid form was chosen with the durability of the Egyptian pyramids in mind — a memorial designed to outlast time. The monument was officially named Sunandha Memorial — Sunandhanusawari.

Phlio is not simply a place where people come to swim. It is a landscape where nature became intertwined with one of the better-known personal stories of Thailand’s nineteenth-century monarchy.

Ang Sarn, Ang Song & Phra Narai Cave

Ang Sarn

A former pavilion near the stream, reportedly from the reign of Rama IV. Erosion and stream force destroyed it in 1974 — now part of the landscape’s memory rather than an intact attraction.

Ang Song / Ang Hong

A small stream and pool associated with a rock formation resembling a swan’s tail, historically connected with bathing activities of Rama IV and Rama V.

Phra Narai Cave

Traditionally associated with a natural water source; historical tourism information describes a cave approximately one kilometre long with water still emerging. Access conditions should be checked with park staff.

Water preserves some things. And destroys others.

Beyond Phlio: Other Waterfalls

Namtok Makok lies farther from the main tourist centre and is part of the park’s network of forest streams and waterfalls. Multiple waterfalls demonstrate that the park protects an entire mountain drainage system — not simply one scenic feature.

Huai Ta Bo Reservoir

A quieter side of Namtok Phlio

One of the more recent visitor attractions within the park is Huai Ta Bo Reservoir. Surrounded by forest, it provides a much calmer landscape than the busy waterfall area — suited to walking, photography, picnicking, relaxing, camping and early-morning scenery.

DNP’s February 2026 information describes the area as open daily from 08:00 to 16:30, with ticket sales ending at 16:00. Early morning mist over the reservoir is highlighted as a particularly attractive time to visit.

Nature Trails

The most accessible trails around the main park area introduce visitors to tropical forest structure, streams, plants, rocks, wildlife habitat and watershed ecology.

Historical TAT information describes a 1,200-metre ecological study trail near the national-park headquarters, taking approximately 45 minutes under normal conditions. Other routes extend farther into the forest. Trail conditions can change with rainfall and maintenance — current information from park staff should take priority over historical distances.

The Meaning of “Phlio”

The origin of the name Phlio is not entirely settled in published tourism sources. One commonly repeated explanation connects it with the language of the Chong people, an Indigenous group historically associated with the Chanthaburi region, with a meaning related to sand or sandy ground. Another explanation links the name to a local plant associated with sandy soil.

Because published sources differ on the precise etymology, ThailandLover presents this as a traditional/local explanation rather than an established linguistic fact. The Chong are part of the cultural geography surrounding Chanthaburi — the name Phlio belongs to a landscape with a much older cultural history than the national park itself.

Climate & Best Time to Visit

Namtok Phlio lies in a humid part of eastern Thailand. Rainfall is an important part of the area’s ecology. Phlio’s streams are known for maintaining water through much of the year, but the character of the waterfall changes with rainfall.

May – October

Best for water. Stronger streams, greener forest, fuller cascades — also slippery surfaces and rapidly changing conditions.

November – February

Comfortable for exploring. Cooler walking weather; good for combining waterfall, history and other Chanthaburi attractions.

March – April

Hotter, but still green. Flow varies with rainfall; early mornings help avoid the strongest heat.

How to Get There

From Chanthaburi city, follow Sukhumvit Road / Highway 3 toward the east. The park entrance is approximately 14–15 kilometres from the city area. Historical tourism information places the turn toward the waterfall around the 347-kilometre marker on Highway 3, followed by a short drive to the park.

The main road is paved and the waterfall area is relatively accessible — one reason Namtok Phlio suits travellers who want a nature experience without committing to a remote mountain journey.

From Bangkok

The most straightforward route is generally Bangkok → Chon Buri → Rayong → Chanthaburi, then continue toward the Phlio area along Highway 3. Allow extra time during weekends and holidays.

How Long Should You Spend?

Quick visit

1.5–2 hours — waterfall, fish, Alongkorn Chedi and Sunandha Memorial.

Half day

3–5 hours — forest walks, time beside the water, monuments and photography without rushing.

Full day

Combine Phlio Waterfall, Huai Ta Bo, a nature trail, another waterfall and Chanthaburi town.

A good ThailandLover day

• Morning — Namtok Phlio Waterfall. Arrive early for softer light and cooler air.
• Late morning — Alongkorn Chedi + Sunandha Memorial. Take time with the history.
• Afternoon — Huai Ta Bo Reservoir. Slow down, walk, photograph the forest.
• Evening — Return to Chanthaburi for old town, food or the waterfront.

Swimming & Water Safety

The clear pools around Phlio are historically known as places where visitors can enter the water. However, this is a natural mountain stream. Conditions can change rapidly after heavy rain. Current park rules, designated swimming areas and safety warnings must always take priority.

The fish may swim around people in the water — part of the natural experience. Avoid grabbing, chasing or otherwise disturbing them.

• Watch your footing on wet rocks
• Do not enter strong currents
• Do not swim after heavy rainfall if officials advise against it
• Keep children within sight
• Do not climb unstable rocks
• Follow signs, barriers and temporary closures

Facilities, Fees & Hours

The main visitor area has parking, toilets, visitor information, food and refreshment areas, walking routes, viewing areas and camping facilities in designated locations. Facilities differ between the main waterfall area and remote ranger stations.

Park fee group

DNP National Park Group 2

Thai visitors

Adult THB 40 · Child THB 20

Foreign visitors

Adult THB 200 · Child THB 100

Vehicles

4-wheel THB 30 · Motorcycle THB 20

Huai Ta Bo hours (Feb 2026 DNP)

08:00–16:30 daily · ticket sales end 16:00

Camping (own tent)

Approx. THB 30 per person per night at Huai Ta Bo · verify current system

These are DNP’s published rates and hours at the time of writing. Fees, opening arrangements and camping policies can change — confirm before travel.

What to bring

• Comfortable walking shoes — forest paths can be wet and slippery
• Swimwear only if swimming is currently permitted
• Towel, drinking water and insect repellent
• Rain protection in the wet season
• Dry bag for phone and camera
• Binoculars for birdwatching

Photography & Wildlife Etiquette

Namtok Phlio is a versatile photography destination: waterfall rocks and vegetation as foreground, fish through clear water, forest layers and filtered light, moss-covered monuments, and early mist at Huai Ta Bo.

• Do not capture animals or remove wildlife
• Do not collect plants or damage rocks
• Do not disturb nests
• Do not play loud music
• Do not leave food waste or plastic in the forest

The park’s greatest attraction is a living ecosystem. Keep it alive.

Conservation

Namtok Phlio protects more than scenery. The forest protects water. The streams support aquatic life. The mountains provide habitat. The vegetation stabilises slopes and contributes to watershed function. And the protected landscape preserves historical monuments that would be much harder to maintain without the surrounding forest.

A natural heritage site — and a cultural heritage landscape.

The Park’s Historical Timeline

1870s

King Chulalongkorn and Queen Sunandha visit Phlio Waterfall. Official sources differ on 1873 vs 1874.

1876

Alongkorn Chedi constructed from laterite.

1880–1881

Queen Sunandha dies in a Chao Phraya barge accident (1880). Sunandha Memorial Pyramid built at Phlio (1881).

1975

Established as Khao Sa Bap National Park — Thailand’s 11th national park.

1982

Renamed Namtok Phlio National Park (approved 29 September 1982).

2026

DNP continues to promote the park as both a natural and historical destination.

The park was originally named for the mountain range. Later, the name changed because Phlio Waterfall had become the area’s most recognisable natural attraction. Older scientific and travel literature may still refer to Khao Sa Bap National Park when describing what is now Namtok Phlio.

Namtok Phlio & Chanthaburi

The park works particularly well as part of a broader Chanthaburi itinerary — rainforest, waterfalls, fruit orchards, historic architecture, gem trading, Catholic heritage, coastal landscapes, fishing communities and local food. Namtok Phlio adds the natural and historical dimension.

TAT includes Namtok Phlio in its recommended two-day Chanthaburi itinerary alongside attractions such as Khao Laem Sing, Laem Sing Beach, Wat Mangkon Buppharam and Khuk Khi Kai.

Not just a waterfall. Not just a historical monument. A place where the two overlap.

Is Namtok Phlio Worth Visiting?

For travellers looking for a combination of nature + swimming + wildlife + history + easy access, Namtok Phlio is particularly distinctive. It is also one of the better national parks for visitors who do not want a demanding multi-hour mountain trek. The main attraction is close to visitor facilities; the historical monuments are nearby; and the fish-filled pools provide an immediate connection with the natural environment.

Essential Information

Official name

Namtok Phlio National Park

Thai

อุทยานแห่งชาติน้ำตกพลิ้ว

Province

Chanthaburi

Districts

Mueang Chanthaburi, Laem Sing, Khlung and Makham

Area

Approximately 134.50 km² / 84,062.5 rai

Mountain range

Khao Sa Bap

Elevation

Approximately 20–924 m

Highest point

Map Wa Krok area, approximately 924 m

Established

2 May 1975 · National park no. 11

Original name

Khao Sa Bap National Park

Renamed

Namtok Phlio National Park, 1982

Main attraction

Phlio Waterfall

Signature wildlife

Stone-sucking carp / Soro brook carp

Historical monuments

Alongkorn Chedi · Sunandha Memorial Pyramid

Other attractions

Khlong Narai, Trok Nong, Makok, Huai Ta Bo Reservoir, forest trails

Nearest city

Chanthaburi · approx. 14–15 km

Main road

Highway 3 / Sukhumvit Road

Frequently Asked Questions

Where is Namtok Phlio National Park?

In Chanthaburi Province, eastern Thailand, covering parts of Mueang Chanthaburi, Laem Sing, Khlung and Makham.

How far is Namtok Phlio from Chanthaburi city?

The main waterfall area is approximately 14–15 kilometres from Chanthaburi city.

What is Namtok Phlio famous for?

Phlio Waterfall, clear stream pools, large schools of stone-sucking carp, and two royal-era monuments: Alongkorn Chedi and the Sunandha Memorial Pyramid.

Can I swim at Phlio Waterfall?

Swimming has traditionally been permitted in designated pools, but conditions and regulations can change. Always follow current park staff instructions, especially after heavy rain.

What are the fish in Phlio Waterfall?

Stone-sucking carp or Soro brook carp, locally pla phluang hin — freshwater fish of clear mountain streams, present in very large numbers according to DNP.

What is Alongkorn Chedi?

A laterite chedi constructed in 1876 in connection with the royal visits of Rama V and Queen Sunandha Kumariratana.

What is the pyramid near Phlio Waterfall?

The Sunandha Memorial (Phra Nang Ruea Lom Pyramid), built in 1881; part of Queen Sunandha’s ashes was placed inside.

Did Rama V visit Phlio Waterfall?

Yes. Sources agree on the visit and his admiration; they differ on whether the relevant year is 1873 or 1874.

When was the park established?

As Khao Sa Bap National Park on 2 May 1975 (11th national park); renamed Namtok Phlio in 1982.

How large is the national park?

Approximately 134.50 km² / 84,062.5 rai.

Are there other waterfalls?

Yes — Khlong Narai, Trok Nong and Makok, among other streams and cascades.

Can I camp there?

Yes, at designated areas. DNP’s February 2026 information specifically identifies Huai Ta Bo as a camping location.

What is Huai Ta Bo?

A forest-surrounded reservoir within the park — walking, photography, picnicking and camping, especially atmospheric in early morning mist.

How much is the entrance fee?

Group 2 rates: Thai adults THB 40 / children THB 20; foreign adults THB 200 / children THB 100. Vehicle fees are separate.

More Eastern Thailand Nature

Khao Khitchakut National Park

Sacred mountain pilgrimages and forest landscape in Chanthaburi.

Khao Chamao–Khao Wong National Park

Waterfalls and wildlife corridors across Rayong and Chanthaburi.

Khao Sip Ha Chan National Park

Eastern Forest Complex hills linking several Chanthaburi protected areas.

Namtok Khlong Kaeo National Park

Another eastern waterfall park in the wider Chanthaburi landscape.

Khao Laem Ya–Mu Ko Samet

Coastal and island nature on the Rayong side of the east coast.

All Nature & Parks

Browse ThailandLover’s national park guides across the country.