The San Francesco al Monte hotel in Naples, Italy, a former monastery originally carved into the mountain in the 16th century, is a warren of rock tunnels and hidden staircases. The clean, newly plastered surfaces are a stark contrast against the ancient rough stone parts of the property. Nooks and crannies and almost-hidden accessways beg for exploration with a flashlight.

Our room—even our bathroom—had incredible views of the city, the bay, and Mount Vesuvius, from multiple windows. It also came with beautifully packaged amenities, including a large jar of fragrant bath salt. All the room lacked was a bathtub.