One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

This sweet-toothed bear searching for snacks has been a symbol of Madrid for decades.

A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

An ancient Egyptian temple in the middle of Madrid, Spain.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

A detailed pachyderm supports Rome's smallest Egyptian obelisk.

Museum dedicated to literary greats of the Romantic Period is also the home in which Keats met his untimely end.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

Jesus' footprints and the first catacombs in the world.

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

The final resting place of the poets Shelley and Keats.

2300-year-old Roman road connecting the empire.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

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."

This picturesque horseshoe weir was first built in the 1600s to prevent flooding in the town of Bath.

This ancient Egyptian obelisk still bears the wounds of World War I.

The medieval woodcut-style artwork chronicles life in medieval London.

This bewitching Babylonian goddess haunts a hallway of the British Museum.

The bones of two medieval royal lions were discovered at the historic fortress.

An architectural oddity hides in plain sight on this iconic London bridge.

These mysterious Viking chess pieces spent centuries hidden on a remote Scottish island.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

A statue of the legendary Celtic warrior queen who fought the Roman invaders stands in one of the cities she once destroyed.