Colorful boxes placed over the dead are left to rot and crumble.

The stickered marker pinpoints where the only maintained road in the United States crosses into the polar region.

A lasting testament to the Klondike Gold Rush.

This remote fort on the Yukon River is a vestige of the wild Alaska gold rush.

This desert oddity hides in plain sight thanks to a cartographic error and a desert explorer with a punny sense of humor.

A massive hydrovolcanic explosion left a half-mile wide crater in Death Valley.

Hidden amid the tropical forest in the Caribbean Sea are the decaying ruins of the Cocaine King's luxurious island party home.

A 6th-century stone lies at the site of the mythical battle waged between King Arthur and his nemesis Mordred.

This hidden green space is the city's second largest conservatory.

A true Valhalla for cactus and succulent lovers.

Traditional 15th century Chinese garden in the middle of Vancouver.

One of the now-less-hidden floral gems of the "Emerald Necklace."

Built over an abandoned train yard, this hidden gem is full of winding paths and offers gorgeous views of Sydney Harbour.

The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

This hidden sculpture garden full of Wild West art is one of San Antonio's best-kept secrets.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

Set amid the remains of a secret WWII airfield, this barn was preserved as a memorial to Allied agents who parachuted into Europe.

A verdant 17th-century-style garden hidden along Edinburgh’s Royal Mile.

This alley off Edinburgh's Royal Mile contains remnants of the city's seedier history.

Now home to a drinking establishment, this building has a macabre history.

These steps offer a breathtaking view of one of Europe's most besieged fortresses.

This tablet indicates where the tragic monarch returned to begin her tumultuous downfall.

A modern frieze of ancient Grecian mythological figures playing a national pastime.