Largest indoor water park

The largest indoor water-based theme park is reported to be Tropical Islands, Krausnick, Germany, with a 66,000-m² (710,400-ft²) main hall – technically an arch-supported membrane structure – with 14,000 tons (30,864,716 lb) of steel and 107 m (351 ft) high, big enough to contain 8 soccer pitches, hold the Statue of Liberty standing upright and the Eiffel Tower on its side. Opened in 2004 between Dresden and Germany, Tropical Islands was originally an airship hangar, and today is fitted out with a mangrove jungle, 50,000-plant rainforest, Tropical Sea, Bali Lagoon, spa, Angkor Wat-style sauna, themed accommodation venues and evening entertainment. It's even possible to go for a balloon ride inside the dome, while a new foil roof also lets in ultraviolet light, so that guests can get a tan. Tropical Islands can accommodate up to 6,000 visitors per day. The airship hangar was constructed in 1999-2000 on the site of the former military Brand-Briesen military airfield by the CargoLifter company, and was intended for the production of the CL160 airship, a 550,000-m³ (19,423,066-ft³) vessel designed to carry a 160-tonne (352,739.62-lb) cargo. Built by a subsidiary of Siemens, SIAT, the dome roof has a surface area of 70,000 m² (753,470 ft²) and contains over 5 million m³ (176,573,333 ft³) of air. After bankruptcy in June 2002, the site was sold in 2003 to the owners of Tropical Islands.