A monument celebrating the idea of reaching inaccessible places.

An 18th-century Spanish watchtower made entirely of seashell and concrete.

Florida might be at its most surreal in this museum devoted to the famed Spanish artist.

The world's largest bicycle shelter can hold more than 12,500 two-wheelers.

While most bridges allow roads to pass over water, this one allows water to pass over a road.

Atop this former dutch railway office sits an interstellar work of art.

An awe-inspiring giant blue whale jaw bone stands in the center of this Dutch island.

Rich with fauna and flora, nature-lovers can walk across the sea at this UNESCO World Heritage spot.

This centuries-old gothic monster has been converted into a sprawling, glossy bookstore.

This former hydraulic laboratory is now a woodland dotted with old engineering models.

This giant radio telescope would be a rusting ruin if it hadn't become such a beloved relic.

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

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

A wooden street sign is the last remnant of this 400-year-old alleyway.

Stockholm's tiniest statue is of a small boy looking at the Moon.

It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

An ancient Viking runestone hidden in plain view in Stockholm's old town.

A tower marking the spot where Yugoslavia began its resistance against the invading Nazis stands neglected, but not quite forgotten.

This Luxembourg cave is covered in cryptic looking marks left by mining activity.

Unchanged for centuries, this medieval library keeps its books in chains.

The struggle of a small Dutch island against the sea.

Croatia's towering concrete blossom grows from the site of a World War II concentration camp.

A grand Yugoslav memorial to the group of partisans who fought and died resisting western Serbia’s Nazi occupation.

Someone left a Boeing 737 in a field in southern Bali.