The best-preserved Roman site in India.

Cheap pizza and all of your naughty bedroom needs housed in a stunning example of Art Nouveau architecture.

The beautiful tunnel that ran from the lobby to Penn Station is still hidden underneath 34th Street.

The home of one of America's most beloved fictional characters has become a real world landmark.

South of Bologna, a limestone grotto with a protruding waterfall and a floor full of cave pearls.

An average of 33 million gallons of water pour out of the collapsed cave at the heart of this spherical spring.

Every half hour, the flow of this unusual spring cycles between a rush of water and barely a trickle.

Taste freshly foraged yarrow and black locust blossoms at this ambitious cocktail bar.

A gift from Emperor Franz Joseph I to his wife.

One room inside this building mesmerizes all with its parabolic dome.

Lions carved into the rockface adorn these two tombs built into the mountains of Dadan.

Wooden pathways run through this rocky landscape, which legend says was created when a dwarven king pulled down his own castle to stop raiding giants.

This former cannon foundry and castle for the Counts of Flanders is now a public garden.

A fortress on this island housed the mysterious prisoner known as the "Man in the Iron Mask" for more than a decade.

This lush 12-acre site was once named the finest Japanese garden in North America.

A Romanesque sanctuary of calm amid the bustle of downtown Los Angeles.

This stucco building in North Africa was the first American-owned property on foreign soil.

According to legend, this ancient column contains healing properties.

The "largest bathroom stall in the world" offers a unique pit-stop experience.

A waterfall and cave near Arroyo Seco that inspired the writings of D. H. Lawrence, Willa Cather, and Mabel Dodge Luhan.

The former home of Thomson Francis Mason, the mayor of Alexandria from 1827-1830.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

This museum honors the composer of “Swannee Ribber.”

A retirement home for soldiers that can trace its history to the Elizabethan era and beyond.