The Czech ‘Sea World’ has the largest water tank in the country, with a capacity of around 100,000L. Some 4500 living species of fish and sea creatures are on display, with a good (and suitably scary) set of sharks. The cramped interior will be disappointing if you’re used to larger marine-themed amusement parks around the world, though kids will certainly enjoy the experience. Special feeding shows and other special events are held through the week. See the website.