Mines of Paris
Many people confuse mines of paris to the catacombs but they are different.Exploring the mines is unlawful and you could have to give a huge fine. It is said that this place is inhabited by mysterious creatures and spirits. Saying it is easy to get lost here is a small thing , not getting lost is an impossible thing.
Image Source :http://theghostdiaries.com/the-2-most-terrifying-places-on-the-planet/