A island reachable by a causeway at low tide is possibly one of the earliest Western European locations to be identified in text.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Local lore says the devil built this beautiful medieval bridge to help a fleeing bandit.

A stunning 18th-century site where pilgrims ascend by a series of punishing stairs only to return via funicular.

This gaping hole in the middle of a remote mountain lake looks like a portal to another dimension.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.