The Womb

The Utroba Cave, also known as Womb Cave, is an ancient cave sanctuary in Kardzhali Province, Bulgaria. Located in the Eastern Rhodope Mountains near the Ilinitsa village, the cave resembles a human vulva and dates to the Thracian period. Historians believe that it was once used as a fertility shrine. It is known in Bulgarian as Utrobata (Утробата, Bulgarian pronunciation: [oˈtrɔbɐtɐ], lit. 'The Womb') or Peshtera Utroba (Пещера Утроба, [pɛʃtɛˈra oˈtrɔbɐ], 'Womb Cave').

Source: Wikipedia (CC BY-SA 4.0) — https://en.wikipedia.org/wiki/Utroba_Cave