Rainy season, safety and preparation
Jun – Oct
Below the dam — Water rises fast in rain
1–3 hours
Good
6 days ahead
When to go
this week
Tap a day card to see that day’s weather, rain, haze and hourly forecast
Best time to go Best window 06:00–12:00 Little rain
Rain at times — slippery roads, allow extra travel time
Holiday — traffic on the way up and parking fills fast; leave early
Hour by hour
Green band = hours used for the score
Best time to go Best window 06:00–15:00 Little rain · light drizzle possible at times
Holiday — traffic on the way up and parking fills fast; leave early
Hour by hour
Green band = hours used for the score
Best time to go Fine all day little rain through the day · light drizzle possible at times
Thick morning fog with visibility under 1 km — use headlights and drive slowly
Holiday — traffic on the way up and parking fills fast; leave early
Hour by hour
Green band = hours used for the score
Best time to go Best window 06:00–12:00 Little rain
Rain at times — slippery roads, allow extra travel time
Thick morning fog with visibility under 1 km — use headlights and drive slowly
Hour by hour
Green band = hours used for the score
Best time to go Best window 06:00–14:00 Little rain · light drizzle possible at times
Thick morning fog with visibility under 1 km — use headlights and drive slowly
Hour by hour
Green band = hours used for the score
Best time to go Fine all day little rain through the day · light drizzle possible at times
No warnings today — normal road and weather conditions
Hour by hour
Green band = hours used for the score
Starry sky
How likely
Scored from cloud cover at every level and tonight’s moonlight — the darker the sky, the clearer the Milky Way · tap another night below for the next 7 nights
Khun Dan Prakan Chon Dam
Khun Dan Prakan Chon Dam, a royal-initiative project at Hin Tang, Mueang Nakhon Nayok.
- Morning light, cool air
- Harsh sun, no shade
- Evening light over the reservoir
Arrive 17:00
- Crest roadLong straight line with the hillsMorning
- SpillwayWhen water is releasedRainy season
- Reservoir edgeSunsetEvening
- Elephant fountain roundaboutDam entranceDaytime
Gallery
Photos from Wikimedia Commons and contributors · full credits inClassic page
Good to know here
Water rises fast in rain
Strong sun and wind
- Come early or late; there is no shade on the crest. Bring a hat and water
- For Khao Chong Lom, buy a boat at the pier on the crest — about 1,500 THB for 1–7 people
- Combine with Nang Rong Waterfall and Wang Takrai Park nearby
- In heavy rain, check Royal Irrigation Department notices before swimming below the dam
Adults 0 THB · Time needed 1–3 hours
Weekends and long holidays
| Crest tram optional | 30 ฿/person |
| Boat charter to Khao Chong Lom (1–7) optional | 1,500 ฿/boat |
Cash · Prices may change by season — check with the venue
- Kids Good; supervise near water
- Seniors Good; tram and golf carts on the crest
- Wheelchair Crest road is smooth and partly usable; the Khao Chong Lom trail is not
- Pets No ban found; keep pets near the car park
- Khundan coffeeCafé on the dam crest
- Lung Pao boat noodlesNear the dam entrance
- Roadside restaurants on Hwy 3049Many along the Sarika–Nang Rong stretch
- Park in marked areas
- Wear a life jacket on boats
- Do not swim in the reservoir
- Do not climb the dam slopes or spillway fences
- Water below the dam can rise suddenly; avoid swimming during heavy rain
- Flash floods hit the area below the dam in Aug 2024 and Sep 2026; follow RID and disaster-agency notices
- Strong sun and wind on the crest
Best months
Tap a month on the wheel to see weather, rain, haze and crowds from 10 years of records
Best time · Oct–Dec for a full reservoir and green hills · Nov–Feb for cool weather · go early or late for softer sun
Watch out · Midday — no shade on the crest · heavy-rain days, when flash floods can hit below the dam
21°Jan
22°Feb
24°Mar
25°Apr
25°May
25°Jun
24°Jul
24°Aug
24°Sep
23°Oct
23°Nov
22°Dec
Oct by the records 23–30°C · avg rain 279 mm (25 rainy days) · clear 2 days · avg PM2.5 11
The story of this place
Khun Dan Prakan Chon Dam, first known as the Khlong Tha Dan Reservoir royal-initiative project, stands at Ban Tha Dan, Hin Tang, Mueang Nakhon Nayok. It dams Khlong Tha Dan as it leaves the Khao Yai range; below it the stream becomes the Nakhon Nayok River. The Royal Irrigation Department runs it through the Khun Dan Prakan Chon Operation and Maintenance Project (Regional Irrigation Office 9).
Read more 5 more paragraphs
Nakhon Nayok suffered repeated floods, dry-season shortages and acid soils. On 9 October 1993, at Thaksin Ratchaniwet Palace in Narathiwat, King Rama IX asked the department to study a reservoir on Khlong Tha Dan and gave a map of the site. He added further guidance on 4 December 1993 at Sala Dusidalai, Chitralada. The Cabinet approved the project on 13 February 1996.
A royal foundation-stone ceremony for the Khlong Tha Dan dam was held on 2 June 2001. Construction began on 2 November 1999. The roller-compacted concrete (RCC) dam is about 2.6 km long and 93–95 m high, using about 4.9 million m³ of RCC. Placement finished in mid-2004, the main works around the turn of 2004–2005, and the reservoir began filling around October 2004–2005 (sources differ). It holds 224 million m³ at normal level, with a four-gate spillway and a 10 MW hydropower plant.
On 5 June 2006 King Rama IX gave the name "Khun Dan Prakan Chon" in memory of Khun Dan (Khun Han Phithak Phraiwan), a frontier officer of Nakhon Nayok in King Naresuan's time who rallied villagers to drive off a Khmer raid; his shrine is at Khao Cha-ngok inside the Chulachomklao Royal Military Academy. "Prakan Chon" means a rampart that holds water. The King formally opened the dam with four other irrigation projects on 7 July 2012.
The dam irrigates more than 185,000 rai, eases floods in the lower Nakhon Nayok basin, flushes acid soils and helps push back salt water in the Bang Pakong River. Its crest became a popular outing, with a tram and boats to Khao Chong Lom and the falls in the reservoir. The dam museum was funded as a royal project from 2004, its five buildings finished in 2007 and later renovated. On 17 March 2021 Princess Sirindhorn named it the Nakhon Nayok National Museum, Phra Borom Chanok Chonlaphat; run by the Fine Arts Department, it was due to open free from 26 June 2021, Wednesday–Sunday 09:00–16:00, covering the dam, irrigation and King Rama IX's work.
Recent years have put its water management in the spotlight. A flash flood hit the area below the dam in August 2024, which the department attributed to rain-fed tributaries. A viral 2025 clip claiming the dam was overflowing was found false. On 26 September 2026 the reservoir passed 100% and all four spillway gates were opened, flooding Hin Tang, Sarika and Si Nawa; releases were later eased with the reservoir at about 96–97%. In July 2026 the Department of Rural Roads opened an elephant-fountain roundabout at the entrance.
- 9 Oct 1993King Rama IX asks for a study of a Khlong Tha Dan reservoir
- 13 Feb 1996Cabinet approves the project
- 2 Nov 1999Construction begins
- 2 Jun 2001Royal foundation-stone ceremony
- Oct 2004–2005Reservoir begins storing water (sources differ)
- 5 Jun 2006Royal name Khun Dan Prakan Chon granted
- 7 Jul 2012King Rama IX opens the dam
See 4 events
- 26 Jun 2021Nakhon Nayok National Museum due to open
- Aug 2024Flash flood below the dam
- Jul 2026Elephant-fountain roundabout opens
- 26 Sep 2026Reservoir passes 100%; all four gates opened
Check-ins & visitor photos
Arrived? Check in, collect a stamp and tell others what it is like right now
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Location must be on and within 0.9 km · One check-in per place per day · come back on other days to check in again
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How to get there
Paved all the way; ordinary cars are fine
Rangsit–Nakhon Nayok Rd (305), then Hwy 3049 · Fuel
From Nakhon Nayok town · Negotiate
Hwy 3049 (Sarika–Nang Rong), then road NY 4016
Large free car park near the crest
Nakhon Nayok town or along Hwy 3049
Good
About 06:00–18:00 (some sources say 08:00–18:00) · boats to Khao Chong Lom 08:00–17:00
around 20 km fromNakhon Nayok town
Khun Dan Prakan Chon Dam
0 THB
Stays near Khun Dan Prakan Chon Dam
Approx. nightly price for 2 adults (next week) · final price depends on your dates
FAQ
Before you goKhun Dan Prakan Chon Dam
Answers travellers want before they go — a one-minute read
Is there an entry fee?
No. Entry and parking are free; the tram, golf carts and boats cost extra
How long is the dam?
About 2.6 km and 93–95 m high — Thailand's longest roller-compacted concrete dam
When was it built?
King Rama IX asked for a study on 9 Oct 1993. Building began 2 Nov 1999, storage began around Oct 2004–2005, the name was granted on 5 Jun 2006, and the King opened it on 7 Jul 2012
What does the name mean?
King Rama IX gave the name in memory of Khun Dan, who defended Nakhon Nayok in King Naresuan's time. "Prakan Chon" means a rampart holding water
How do I get to Khao Chong Lom?
Charter a boat on the crest, about 1,500 THB for 1–7 people: 15–20 min by boat, then about 400 m on foot
Can I swim?
Not in the reservoir. People swim below the dam, but it is risky when water is released or after heavy rain
Ready to go to Khun Dan Prakan Chon Dam?
Best day this week: Wednesday 28 Oct · Check in when you arrive to collect a stamp