The prototype for all Nazi concentration camps.

A fearsome dragon clings to a corner of Munich's city hall.

The site where hundreds of Greeks were tortured by the Nazi secret police is now a cosmetics store.

The only surviving choragic monument is a trophy awarded in 334 BC for the winning dramatic chorus.

Cold war icon and onetime "hole" in the iron curtain.

Berlin's beloved bear is immortalized at the Museum für Naturkunde.

A small cell adjacent to this church was once the bedroom for a renowned saint.

A fortified medieval basilica on the Caelian Hill preserves extraordinary frescoes and one of Rome's most beautiful hidden cloisters.

Its interior is adorned with some of the best examples of early Christian mosaics.

This ancient Roman arch misled treasure hunters for centuries.

A rather vulgar example of the transition from Latin to the Italian vernacular.

Remnants of a 4th-century church with vivid medieval frescoes and ancient sarcophagi hide beneath this old basilica.

The best preserved Paleochristian basilica in Rome hides a number of oddities and secrets.

The mystic whose incorrupt corpse still attracts the faithful.

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

A Nesting Doll of Churches.

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

Rome's semi-secret peephole vista is also a former Crusader stronghold.

The yawning maw of this pagan visage is said to bite off the hands of liars.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

A man's head is enshrined beneath a statue near the first building constructed for the modern Olympic Games.

The ruins of an abandoned medieval city where the last Byzantine emperor was crowned.

This smily stone feline is meant to represent a mythical lion that almost destroyed the island of Kea.

The ruins of this monumental city founded by the first Roman Emperor are strangely overlooked by most travelers.