Rayong Aquarium

Rayong Aquarium is a government-run marine research and education facility in Phe subdistrict, a few minutes from Ban Phe pier — the jumping-off point for ferries to Koh Samet. Run by the Department of Fisheries rather than a private operator, it charges a flat 30 THB for adults regardless of nationality, with no separate foreigner rate — unusual for a Thai attraction and worth knowing if you’re used to dual pricing elsewhere. Children pay 10 THB, and anyone under 120cm tall or over 60 gets in free.

The centrepiece is a glass tunnel tank you walk through, surrounded by fish and mangrove-dwelling creatures on all sides: cuttlefish, mud crabs, giant clams, and horseshoe crabs, alongside the reef species you’d expect. Outdoor turtle ponds hold hawksbill, olive ridley, and leatherback turtles — three of Thailand’s most endangered marine species — and a separate touch-friendly pond lets you get close to starfish, anemones, and sea cucumbers without a glass barrier in the way. A side hall displays miniature traditional fishing gear used along this stretch of the Gulf coast.

Insider Tip: The Fossil Museum section, tacked onto the main building, is easy to walk past — it houses taxidermy and skeletal displays of rarer animals, including Irrawaddy and humpback dolphins, both found in Thai coastal waters but rarely seen up close. It’s included in the same ticket, so don’t skip it.

Watch out: Hours are limited and the aquarium closes two days a week. It’s open Wednesday to Friday 10:00-16:00, and Saturday, Sunday, and public holidays 10:00-17:00 — closed Monday and Tuesday entirely. Call ahead (0 3865 3741) if you’re routing a visit around a Koh Samet ferry.

As an education-first facility rather than a polished tourist attraction, don’t expect the production values of Bangkok’s SEA LIFE or Phuket Aquarium — tanks are functional, signage is mostly Thai, and the focus is conservation and research over spectacle. Seafood products caught locally are sold at a small stall outside. It’s a reasonable hour-long stop if you’re already passing through the Mae Phim Beach area toward Ban Phe or Koh Samet, particularly with kids, but not a destination to build a day around on its own — pair it with a stop at Laem Mae Phim or the Rayong Botanical Garden nearby.