The World's Largest Ice Cave in Salzburg, Austria

One of the true wonders on earth, the Eisriesenwelt caves are a wondrous underground world of natural ice sculptures and formations and the largest of its kind. Eisriesenwelt means "world of the ice giants" in German.Its is a labyrinth of natural limestone ice caves, located within the Hochkogel mountain in the Tennengebirge section of the Alps, in Werfen, Austria, about 40 km south of Salzburg, and stretch for a remarkable 40 kilometers. Only the first kilometer is covered in ice, thats the area that tourists are allowed to visit, but it's enough to get a feel of what the remaining network would be like: a truly mesmerizing art of nature's handicraft. The rest of the cave is formed of limestone. The cave is open to tourists from May 1st to October 26th every year. 

There are various ways in which a cave ice can form. The Eisriesenwelt is a dynamic cave, which means the corridors and the crevices connect lower lying entrances to higher openings, thus it makes it possible for draughts of air to circulate – similar to the effect in a chimney. During spring, melt water seeps through the cracks in the rock and when it reaches the still cold and frozen lower areas of the caves it freezes and turns slowly into the wonderful ice formations visible inside the caves. 

Eisriesenwelt was formed by the Salzach river, which eroded passageways into the mountain. The ice formations in the cave were formed by thawing snow which drained into the cave and froze during winter. Since the entrance to the cave is open year-round, chilly winter winds blow into the cave and freeze the snow inside. In summer, a cold wind from inside the cave blows toward the entrance and prevents the formations from melting.

The first official discovery of Eisriesenwelt was by "Anton Posselt", a natural scientist from Salzburg, in 1879, though he only explored the first two hundred meters of the cave. Before his discovery, the cave was known only to locals who believed that it was an entrance to Hell and refused to explore it. "Alexander von Mork", a speleologist from Salzburg led several expeditions into the caves beginning in 1912, which were soon followed by other explorers.Eisriesenwelt cave fetches around 200,000 tourists every year.

Source