The Summer Cave at the Grotta Palazzese, Italy
The Grotta Palazzese Hotel in Polignano a Mare, Italy, is home to a restaurant in a limestone cave. The Summer Cave, as its name suggests, is open only during the summer, usually from May to October.
From the cave setting, diners look out onto the turquoise waters of the Adriatic Sea as waves splash shadows onto the walls. Fodor's Travel calls The Summer Cave the most romantic restaurant in all of Italy.
Online reviews tend to rave about the atmosphere while giving the food mixed reviews. And this probably won't surprise you: It's also expensive.