The signs of a long buried road can still be found hidden beneath a London sewer grate.

The site of London’s first coffee house has been serving refreshments of one kind or another for 360 years.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

This alley off Edinburgh's Royal Mile contains remnants of the city's seedier history.

A labyrinthine network of chambers with a storied past hides below Edinburgh's South Bridge.

There was a top secret plan during World War II to seal a group of soldiers inside the rock.

Single runway interrupted by a busy road that cuts across its middle.

The largest oak in England is said to have been the hideout of Robin Hood and his Merry Men.

A historic observatory precariously perched at the "Top of Europe."

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

An 11th-century runestone decorates the halls of Terminal 2 of this Scandinavian travel hub.

The library's graceful rotunda is like a bibliophile's temple.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Spanish architects used seized Muslim gravestones to rebuild parts of the fortress.

One of the most spectacular bridges in Spain spans a narrow chasm that divides the city of Ronda.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona’s iconic (but controversial) church was finally completed in 2026—a century after the death of its architect.

A memorial for a young woman and her ghost, which are claimed to have caused countless deathly shipwrecks.

The only museum with its curator—and her pets—buried inside.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Go inside to really appreciate this 500-year-old technological masterpiece.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

The mummified relic of St. Antoninus.