Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

Two New York rooftops are home to the largest rooftop soil farms in the world.

A crumbling hospital from the 1850s on Roosevelt Island.

Residential building on the Regents Canal is a breeding ground for creativity and innovation.

A Roman spa buried deep beneath the City of London.

Following the trail of an old metro line, this scenic path is haunted by a creepy spriggan statue.

Abstract dinosaur models in London.

A historic house left in "dramatic still life."

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

The final resting place of infamous outlaw Clyde and Marvin Barrow.

Giant heads occasionally litter the industrial Houston neighborhood where sculptor David Adickes has his studio.

In Paris, Texas they have their own Eiffel Tower, it just has a cowboy hat on it.

These boots are made for selfies.

This small town Texas cemetery is said to be the burial site of a UFO pilot who crashed in the 1800s.

Visitors can walk over the largest concentration of Columbian mammoths to have died from one event.

An abandoned quicksilver mining town surrounded by the Big Bend parks.

The Grand Canyon of Texas.

A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.

An emerald-green grotto just a short trip from Austin.

Belly up to the bar in Cowtown, don't forget to buy some boots.

The final resting place of an outlaw, whose legend grew after death.

A trio of colossal statues spread across a Dallas neighborhood chart the emergence of a giant robot born of a locomotive and spilled gin.

Visit this playground of waterfalls, caves and sinkholes.

This Elizabethan hedge maze is one of only six in North America.