Eisriesenwelt

Eisriesenwelt, meaning "World of Ice," is a limestone ice cave located in the Tennengebirge mountains near Werfen in the Salzburg region of Austria. It is the largest ice cave in the world by total length. The cave was discovered in 1879 by Austrian explorer Anton von Posselt-Czorich-Rustschitz and has been open to the public since 1913. It is protected as a natural monument.

Geology and climate: The cave forms in the limestone of the Northern Limestone Alps. Water entering the cave freezes in the cold, resulting in ice formations such as icicles, draperies, and ice columns that persist year round. The interior temperature remains close to freezing, creating a stable ice environment even in summer.

Size and interior features: The cave system extends more than 42 kilometers, making it the largest ice cave by length. The portion accessible to visitors runs for about 1.5 kilometers and includes notable spaces such as the Ice Palace (Eispalast) and other ice-filled chambers.

Visit and access: Visitors reach the cave via a visitor center at Werfen, with guided tours lasting about 70 minutes inside the cave. The route involves stairs and narrow passages and is typically offered during the warmer months; tours may be limited by weather or safety considerations.