It turns out that there already is. 60 km south of the German capital is the world's largest indoor tropical island, with the world's largest area of tropical forest, where it grows 30 thousand trees, shrubs and other vegetation.
The dimensions of this giant water park is really stunning - 360 meters long, 210 wide and 108 meters high. Total area - 66 thousand square meters. Such an area roughly equal to the area of eight football fields and the height allows to hide inside the Statue of Liberty (vertical) and the Eiffel Tower (horizontally). Approximate capacity of artificial resort - 7,000 visitors at a time. The original name of facilities - «Tropical Islands Resort». The air temperature is consistently 25 degrees Celsius, and water - +28.