Scattered throughout London are ancient remnants of the city's former bounding wall.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

Famously misunderstood wonder of the ancient world

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

An alleyway plaque is all that remains of the independent Texas' envoy that forgot to pay their rent for over a century.

This massive fiberglass Gulliver turns every visitor into a Lilliputian.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

The world's tallest statue of an American hero.

A private collection of massive steel monsters guarding a Texas pipe works.

A health museum containing a 27’’½-foot intestine.

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

This staircase full of Mayan hieroglyphics is perhaps the largest single text in the world.

A full-size replica of this well-preserved temple lets you take a walk through the Mayan age.