The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

All that's left of the quintessential "cabin in the woods."

A terrific purveyor of natural history objects and curios.

During prohibition, corrupt city officials ran drinking dens under the streets of Downtown Los Angeles.

A huge musical instrument played by the ocean.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

One of the best places to see feral Colonial Spanish Mustangs in the United States.

148 feet long and in the middle of a verdant forest.

One man has spent decades faithfully constructing this unique brick and cinderblock castle.

This abandoned bridge to nowhere stands secluded in the woods of a Cleveland suburb.

Scattered around Atlanta are little doors with big charm.

Swarovski's museum/theme park is a fake diamond fantasia overlooked by a giant.

Visit a surreal landscape so otherworldly NASA actually used it to train the Apollo 17 crew.

This pre-Revolutionary War grist mill ground corn and flour for soldiers in seven American wars.

The remnants of a wooden-hulled fleet built and abandoned in WWI, now home to a thriving ecosystem.

The remains of a failed attempt at medieval nerdery are hidden deep in the woods of Virginia.

The ruins of this Thomas-Jefferson-designed mansion have been left to crumble since the Christmas Day they burnt down.

This ancient ruined monastery has been destroyed by fire so many times that it seems like God hates it.

This tri-part waterfall is a little bit of fairytale beauty in the heart of Luxembourg's Little Switzerland.

The last bastion of Roman presence north of the Alps looms over a German town.

A former ironworks that was the first UNESCO industrial site.

The beautiful baroque library of the Hapsburg empire.

The largest and most famous wax anatomical collection anywhere in the world.

A theme park that suffered massive flooding during Katrina was abandoned, and now proves irresistible to trespassing explorers.