This once architecturally advanced housing complex is now a haven for squatters that still bears the scars of war.

The ruined doorway is a portal to the building's turbulent and torturous past.

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

The unexpectedly beloved remnants of a controversial thermal power plant.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

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

A castle from the Holy Roman Empire that hosts traveling youth... in its stables.

This abandoned coliseum was intended to be a grand Nazi rallying ground before it was halted at the end of the war.

A series of haunting wooden totems are hidden in the woods surrounding a German environmental center.

Tourists often confuse this beautifully ornate former cigarette factory for a mosque.

When the rain falls, this drain system turns into a musical instrument.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Every equinox this Maya pyramid puts on a spooky ancient light show.

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

A detailed pachyderm supports Rome's smallest Egyptian obelisk.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.

Scattered throughout London are ancient remnants of the city's former bounding wall.

This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.

An unusual round church in London with a Templar past.

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