Kahlenberg

The Kahlenberg (German pronunciation: [ˈkaːlənˌbɛʁk] ⓘ) is a hill (484 m or 1,588 ft) located in the 19th District of Vienna, Austria (Döbling).

Two terraces are located on the mountain: one at a small church called St. Josef and one at a restaurant built in the 1930s by architect Erich Boltenstern.

After acquiring the mountain, Ferdinand II allowed a hermitage for the Kamaldulenser, an order of Catholic hermits, to be built.

Jan III Sobieski, King of Poland launched his attack on the Turkish forces during the second siege of Vienna from here.

The mountain is also notable as the place where Albert Einstein, Otto Neurath, and other mathematicians and physicists made the first plans, around 1920, for what would later become the International Encyclopedia of Unified Science.