7. Beelitz-Heilstätten, Germany
This abandoned sanatorium near Berlin was once used to treat tuberculosis patients before it fell into disrepair. During WWII, the site was repurposed as a military hospital. The dilapidated buildings and overgrown grounds are now a breeding ground for urban legends and ghost stories. Its creepy corridors and decaying hospital rooms evoke a sense of unease, and its chilling history continues to attract those brave enough to venture inside.