🇵🇹Benagil Cave, Algarve, Portugal
It is difficult to imagine that man is not involved in the creation of this masterpiece, it is a creation of nature. It was formed as a result of exposure to rain and sea water. This natural wonder is located about 300 meters from the beach of the same name. You can get to it in the morning from Benagil beach by boat, paying a symbolic amount.
https://goo.gl/maps/u2JwCYLSrvWjGSg78