An abandoned railroad tunnel is now filled with bioluminescent bugs.

A communal oasis on Lake Zurich.

The steepest classic funicular in the world glides along a dizzying incline.

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

The site where a plot to assassinate Hitler was planned—and its conspirators were executed—is now a powerful memorial to the German resistance during World War II.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

A monument to the man who almost killed Hitler.

19th century museum with an eclectic mix of curiosities, from Egyptian artifacts to items on archery history to the skull of the world's oldest horse.

Constructed on the ruins of a convent, this tower saved countless lives.