One of the biggest underground aquariums in the region, Siam Ocean World is home to over 30,000 marine creatures from all over the world, including sharks, octopus, seals, stingrays and more. Located near several large hotels in Bangkok, such as Chatrium Hotels & Residences, for example, the central location and impressive displays make the aquarium a great place for a day out. Inside, there is 7 enclosures for different environments such as Living Ocean, Deep Reef and Sea Jellies. Walking around the displays are fascinating enough, but if you want to get even closer to the marine life, Ocean World provides visitors with the opportunity to dive into the oceanarium with an instructor.