Eisriesenwelt–The World’s Largest Ice Cave, Austria. The Eisriesenwelt (German for “World of the Ice Giants) is a natural limestone ice cave located in Werfen, Austria, about 40 km south of Salzburg. Although the cave has a length of 42 km, only the first kilometer, the area that tourists are allowed to visit, is covered in ice. Eisriesenwelt was discovered by Anton Posselt, a natural scientist from Salzburg, in 1879. Before his discovery, the cave was known only to locals, who, believing that it was an entrance to Hell, refused to explore it. Today the Eisriesenwelt cave is visited by around 200,000 tourists every year.
The karst landscapes of China have been an essential part of their figurative art and painting since time immemorial, capturing the imagination and providing a sense of wonder at nature. The sinkholes here form when underground rivers carve out underground channels by chemical erosion whose roofs later collapse when they weaken. These windows allow sunlight to pour within, and extensive and unique ecosystems to develop underground.