Aerial view of the Grotta della Poesia (Poetry's Cave) near Roca, Lecce, Italy

Pretty poetic for a pit

Taking a bird's-eye view along the coast of Italy's bootheel, you'll spot many coves and caves like this one, the Grotta della Poesia. In English, that's Poetry's Cave, a sea-flooded sinkhole so named for the ancient poets who—legend has it—were bemused by a beautiful princess who often came here for a dip.

Nowadays it's a popular spot for all water lovers, regardless of royal standing. Inside the sinkhole, an underground cavern carries the clear waters out to sea, beckoning the most intrepid swimmers and scuba divers toward the open Adriatic.