The most unusual block in Brasília.

A series of concentric circles represented a bold new experiment in socialist urban planning, and it notoriously difficult to get around.

Planned as the world’s first zero-carbon city, it had lofty ideals—but is only 5 percent completed and aiming for 50 percent carbon-neutral.

The birthplace of both the Atomic Age and Godzilla, and the namesake of the bathing suit.

Once the path of a railway tunnel, now home to thousands of glowing insects.

A galaxy of glowworms—larvae of a gnat—hides deep in the belly of these caves.

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

This medieval castle was painted pink as part of a now-abandoned children's theme park.

At this small shop off a dirt road in the forest, the specialty is eel the owner caught and smoked himself.

A fitting attraction for the corn capital of the world.

A stone copper was sculpted on the wall of the Carlisle Cathedral to honor a local hero.

This century-old grotesque has a mysterious history and may not actually be a rabbit.

If it hadn't been caught in time, a flaw in the design of this Manhattan skyscraper could have led to its collapse.

Someone really, really wanted to save this fast-food icon from demolition.

The largest single concentration of harmless garter snakes in the world is a writhing Canadian serpent orgy.

One of the first amphibian migration tunnels in the United States encourages a tradition that has inspired Amherst residents for decades.

Special tunnels built so that frogs won't be killed when crossing the highway.

This psychedelic tourist trap is a leisurely descent into madness.

More stones than Stonehenge, all scattered within a windswept landscape sure to enchant 'Outlander' fans.

A museum dedicated to secret surveillance.

The remains of a historic football stadium that once hosted 50,000 spectators.

It's safe—and permitted—to walk across these twin natural sandstone arches.

Germany's Glienicke Bridge has a shady history of clandestine meetings, espionage, and spycraft.

An abandoned quarry hides an open-air gallery of huge sculptures, some made from the rubble of 9/11.