One of the largest aquariums in Europe, this South Bank attraction boasts 350 species of fish, including everything from British freshwater species to brightly colored tropical clownfish. The tanks are ordered geographically, so you can observe the bountiful riches of the coral reefs of the Indian Ocean, or what lurks in the murky depths of the Atlantic and Pacific oceans, including an array of eels, turtles, squid, jellyfish, and seahorses. As ever, the stars are the sharks. There are more than 40 of the toothsome beasts here, including some scary-looking sand tiger sharks. Many are housed in the Shark Walk, where you can watch the killers of the deep swimming beneath your feet. Other highlights include a touch pool for rays -- who do seem to get a dog-like satisfaction from the experience -- and a replica tropical rainforest, home to a set of crocodiles. The seawater, incidentally, is just normal Thames water mixed with 8 tons (17,920lbs) of salt.