Buried for centuries, this hidden cellar is all that remains of London's medieval Whitefriars Monastery.

One of the few remaining relics of the meatpacking hub that made Chicago the "hog butcher to the world."

The remains of this rugged homestead ranch offer a brief glimpse into a bygone era.

A Byzantine church containing the holy remnants of three saints sits atop the site of an ancient temple.

A nature and cultural preserve named for its multitude of petroglyphs carved by the Northern Sinagua people.

The best preserved Paleochristian basilica in Rome hides a number of oddities and secrets.

A forgotten relic from New York's bygone trolley system hides in plain sight under a bridge.

This Georgian Gothic building was created to shelter and feed deer.

A treasure trove of rare and exquisitely detailed antiques

The quirky gift from West Berlin for the 1968 World's Fair still stands in Hemisfair Park.

Not far from Madrid, a set of perfectly preserved trenches date back to the Spanish Civil War.

These abandoned grain silos and tunnels are an urban exploration dream.

Its front wall is striped with a menagerie of fantastic beasts and magnificent monsters.

The patron of this extravagant Art Nouveau confection insisted that nothing less than a boat should project from its facade.

This secluded walkway overlooks a magnificently wild London green space.

A French artist's vague warning hangs over Belleville.

Explore Hull's historic Old Town by following the sea creatures scattered throughout its charmingly cobbled streets.

Hidden on a cattle ranch in Arizona, this bookstore has been celebrating Southwest literature for more than 40 years.

A historic hill of tall tales, with one rather special tree.

Rare wooden escalators lead deep down into an otherwise staggeringly monotonous tiled tunnel.

This Viking gravestone carved in a rare runic style was dug up from a London churchyard.

This Manhattan museum houses one of the largest collections of Spanish art and manuscripts outside of Spain.

A leafy, peaceful oasis nestled in the heart of Glasgow's busy south side.

This museum tucked below a charming cafe gives a brief snapshot of photographic history.