16. Beelitz-Heilstätten Sanatorium, Germany
Adolf Hitler was once treated for battle wounds at this hospital. Beelitz was also used as a rehabilitation center for patients with tuberculosis in the late 19th century.
17. Caddo Lake, Texas
Caddo Lake looks more like a remote swamp forest due to the old, towering cypress trees surrounding the natural lake.
18. Spreepark Abandoned Theme Park, Germany
Chilly night tours were offered for a while after Spreepark closed down in 2002. Imagine hearing weird noises from abandoned amusement park rides at wee hours. Scary.
19. Catacombs of Paris, France
An underground cemetery with overflowing century-old bones tells the history of overcrowding in cemeteries in Paris before.
20. Skull Chapel, Poland
This baroque church is filled with skulls of people who died during Thirty Years War back in the year 1618.