This unreal Portuguese palace looks as though it's made from a pile of different castles.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

This small chapel is built of human bones and decorated with a golden skeleton.

An intricate and amazing house built by architect Karl Junker.

Fantastic views and thousands of love locks.

The architect of this fanciful complex called it an "oasis for humanity and nature in a sea of rational houses."

Climb inside an iron crystal magnified 165 billion times its normal size.

This giant urban staircase was built to keep the city's brave fighting men from getting waylaid in the red light district.

A Belgian self-built tower inspired by the Bible and ancient civilizations.

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

Ghosts of France's colonial past.

A top-secret bunker now turned museum, is an eerie look at what life would have looked like in the event of nuclear war.

This functioning parish church is also the site of many concert performances due to its wonderful acoustics.

The world's northernmost aquarium looks like it has fallen over.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

Stockholm's deepest subway station is also a stunning ecological wonder.

Stockholm's narrowest alley is barely over two feet wide.

This chimerical bridge/tunnel appears to dead end right into the sea.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

Flowers have mysteriously appeared on her effigy every day for the last 150 years.

These paved rills bring freshwater into Altstadt and could spell wedding bells for whoever stumbles into the waters.

In this cobwebbed old operating theater, you can practically hear the screams of the unanesthetized patients.

Moscow's most popular cemetery includes the graves of numerous cosmonauts.