Pasakcholasit Aquarium

Pasakcholasit Aquarium is a free, government-run freshwater aquarium on the grounds of the Pa Sak Jolasid Dam in Phatthana Nikhom district, Lopburi — not Ayutthaya, though the dam is a popular day trip from there, about 40km away. It’s open daily 08:30-16:30 — standard government-office hours — with no admission charge beyond signing the visitor book, showing off the native river and reservoir fish that inhabit the Pa Sak watershed itself. Hours have varied over the years, so call 0 3657 3203 before making a special trip.

The tanks focus on freshwater species found in Thailand’s rivers, lakes, and the Pa Sak reservoir the dam created — a narrower, more locally relevant collection than a typical tropical aquarium, built as much for education as entertainment. Signage explains the freshwater ecosystems these fish come from and the role the dam plays in the region’s water management, tying the aquarium back to the reservoir it sits beside rather than functioning as a standalone attraction. Air conditioning and dim tank lighting make it a welcome break from the heat if you’re visiting the dam in the middle of the day.

Because it’s part of the wider Pa Sak Jolasid Dam complex rather than a destination in its own right, most visitors treat it as one stop on a longer visit that also takes in the reservoir views, the observation tower, and lakeside food stalls. It’s a short, low-key add-on — plan 20-30 minutes rather than a half-day visit.

The dam and reservoir it belongs to are the real draw of the area — Thailand’s largest earth-fill dam, impounding the Pa Sak River across the Lopburi-Saraburi border and creating a lake big enough for fishing trips and boat rides. The aquarium works best framed that way: a small, free, air-conditioned pause between the outdoor parts of a dam visit, not a headline attraction to plan a trip around on its own.

Insider Tip: Combine the aquarium with the dam’s observation tower and lakeside restaurants rather than visiting it as a standalone trip — the whole complex works better as one outing, and the aquarium alone doesn’t justify the drive out here on its own.

Watch out: This is genuinely rural — don’t expect a large modern aquarium on the scale of Bangkok’s SEA LIFE or Sea Life Chiang Mai. It’s a modest, single-hall facility, and public transport to the site is limited, so plan for a taxi or your own vehicle.

The aquarium is on the grounds of the Pasak Chonlasit Dam, in Lopburi’s Phatthana Nikhom district. Bring a camera, though flash photography may be restricted near some tanks.