Rajamangkala Aquarium

Rajamangkala Aquarium sits on the mainland in Sikao district, Trang — not on Koh Ngai island, despite how it’s sometimes filed. It’s part of Rajamangala University of Technology Srivijaya’s Trang campus, run by the university’s Natural Resources and Environment Institute as both a teaching aquarium and a public attraction. Entry runs 50 THB for foreign visitors, 30 THB for Thai adults, with lower rates for students and children. It’s open daily, 09:00 to 17:00.

The aquarium holds more than 70 tanks across its exhibition halls — ranging from 1 to 50 cubic metres — with over 300 species on show. Andaman reef fish, rays, and small sharks native to Trang’s coastal waters sit alongside freshwater displays of arowana, arapaima, and other Amazon imports, plus tanks of seahorses and barb fish. A seal show is the facility’s headline draw: the seals were imported from South Africa and perform for visitors on a rotating schedule, worth checking on arrival since timing isn’t fixed. Because this is a working university institute rather than a commercial aquarium chain, expect academic-style information panels over flashy interpretive displays — useful if you want real detail on the species, less so if you’re after a slick tourist attraction.

Insider Tip: Since it’s a teaching facility first, staff (often students) are usually happy to answer questions in more depth than a typical aquarium ticket-counter employee — ask about the species you don’t recognise.

Watch out: If you’re staying on Koh Ngai and plan a day trip here, budget for both a boat crossing to the mainland (Hat Yao or Kuan Tung Ku pier) and a further road transfer to the Sikao campus — it’s not a short hop, and boat schedules to Koh Ngai thin out considerably by late afternoon.

For the wider mainland area, see the Trang destination guide. If you’re basing yourself on the island instead, Koh Ngai covers what’s actually on the island itself.