One of the oldest scientific gardens in Britain, containing more than 13,302 plant species in its core collection.

Amazing and mysterious Neolithic settlement on Scotland's Orkney Islands.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

The scene of one of the darkest moments in American labor history has been left essentially untouched since the tragedy.

At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.

See six states, pickled freaks, rocks, and antiques.

The site where a nuclear bomb was lowered over 8,000 feet underground and detonated as an experiment in natural gas extraction.

The wreckage of a World War II bomber is hidden high in the Colorado wilderness.

A downtown park built on top of unclaimed graves.

Travel through the wholesome amusements of yesteryear at this charming miniature village.

A mental health hospital dating back more than 139 years, now features a museum.

A futuristic hovertrain is parked unceremoniously alongside a nondescript road.

A prehistoric rock shelter that's literally in someone's backyard.

Final resting place of a 19th century gold prospector and convicted cannibal.

The superstar of Cold War nuclear bunkers has been featured in countless films but is now barely operational.

There are eight natural springs around town, each with a slightly different taste.

The haunted reputation of these abandoned Colorado train tunnels is probably not helped by the terrifying spiked fence.

The clock that sets them all.

Amsterdam's former hotspot for public executions and dissections.

Debatably clever, or just plain honest hotel advertised as "The Worst Hotel in the World."

A rare tour of an aristocrat's private home reveals valuable 17th-century paintings from artists like Rembrandt.

A collection of biblical memorabilia.

A public urinal so pretty, it was declared a national monument.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.