Gambia
Historical; Spiritual
An archaelogical site built thousands of years ago, this is a fascinating peek into ancient West Africa.  Massive stones sit in circles like an African Stonhenge.  Human remains have been excavated from near the site but carbon dating has proven that they were buried there after the stones were actually erected, so the mystery remains. 

A small museum has some information on theories about what the place may have been used for and who used it.