The last moments of the ill-fated Pompeiians, frozen forever in plaster.

Pompeii's less famous neighbor is still revealing her secrets.

This small, ancient Roman temple was once a church dedicated to the patron saint of penitents.

Brass cobblestones mark the places where individual Holocaust victims were taken from their homes.

The martyr's wax-enhanced skeletal remains lie preserved in a glass case in the Santa Maria della Vittoria in Rome.

One of several skulls claiming to belong to the beheaded St. John the Baptist is on display at this Roman church.

The skull of the patron saint of lovers lies in the Basilica di Santa Maria in Cosmedin—maybe.

2300-year-old Roman road connecting the empire.

This medieval city gate is now a blend of the past and the modern world.

The remains of the left arm of the levitating philosopher-saint are kept in a 13th-century Neapolitan basilica.

Skulls from the plague of 1656 and World War II bombings are united by a cult dedicated to caring for the ancient dead.

This grisly effigy displays an early Christian martyr who was skinned alive and beheaded.

Vast network of air raid tunnels beneath Lombardy's capital.

Small on the outside, big on the inside, this church is an astonishing act of visual deception.

The secret medieval communication system will whisk your words above the noise of the crowd.

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

The preserved remains of the former Milwaukee County Hospital for the Insane are hidden in the wooded grounds of County Park.

This solitary gravestone is separated from the rest in Appleton, explaining why local legends continue to surround it.

A remote hill on a stretch of country road where the laws of physics are defied... or so it seems.

Vikings and Evangelicals have both had a hand in this replica medieval church.

An artsy hidden staircase leads to breathtaking views of San Francisco.

The famous author's cottage hideaway.

A dark, dank room in subterranean Manhattan was the site of a ghastly murder.

The fanciest public restroom in New York City boasts fresh flowers, art, and a classical music soundtrack.