Sharjah Aquarium sits by Al Khan lagoon and focuses on the marine life of the Gulf, from reef fish and rays to the smaller creatures that live around mangroves and coastal shallows. It is a compact, family-friendly attraction rather than a huge destination aquarium, but it gives useful local context to a coast many visitors otherwise see only from beaches and corniches.
It pairs well with the nearby Maritime Museum and a walk around Al Khan. For travellers with children, it is also one of Sharjah's easiest air-conditioned stops, especially in the hotter months when outdoor sightseeing gets tiring quickly.