One of the world's heaviest musical instruments towers within a popular urban park.

A traditional U-Bahn station in Berlin gets a string of rather untraditional benches.

The world's first clock to use set theory as a measure of time required the invention of a new light bulb just to maintain its obtuse measurements.

A surreal museum of extraordinary industrial objects.

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

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

This abandoned seaside fortress is now simply an imposing ruin being taken back by nature.

A former seaside jewel built for the everyman is now simply a neglected art deco fortress.

A four story, football field-sized, nine-grotto creation made of shells, minerals, and rare stones.

A spiritual vortex among the red rocks in Sedona.

An eatery for UFO seekers on the Extraterrestrial Highway.

In the middle of an extremely unforgiving and desolate high desert is the most secret military facility in the world.

An earthwork sculpture built by Robert Smithson in the Great Salt Lake only reemerges during drought.

The residents at this Yellowstone wildlife park will certify your cooler as "bear-proof."

A fortress on this island housed the mysterious prisoner known as the "Man in the Iron Mask" for more than a decade.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

Giant eggs, walls of bread, and nightmare surreality mark the largest collection of works by Salvador Dalí.

Once the product of an inexplicable gold strike, this ghost town is now home to one man and his love of classic machines.

The unusual patterns in this rock formation result from two distinct modes of weathering.

On the outskirts of a reborn ghost town, a decaying post office remembers the bad old days.

A huge musical instrument played by the ocean.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

A moody and picturesque riverside ruin overgrown with vegetation.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.