Antwerp Zoo in Belgium has one of Europe&rsquos largest reef aquariums. It is housed in the zoo&rsquos aquarium building, which dates back to 1911. It took two years to grow the coral reef, which is now home to 4,000 fish, belonging to 40 different species.The curvature of the specially designed observation window, with a height of 4 metres, breadth of 8 metres and a thickness of 13 centimetres, will give you a feel of standing among the coral and the fish. For more details, check www.zooantwerpen.be/en