Isaac Newton's former home, where the famous apple tree still stands.

A quartet of rusting satellite goliaths are all that remain of a communication network that protected Britain from German and Russian air strikes.

Seat of the Duke and Duchess of Devonshire for centuries.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

On a site with a long military history, a 1980s shelter.

Each year a new straw behemoth is born.

An open air haven for tropical monkeys in the damp moors of the English country.

6000-year-old site covered in more than 50 megaliths.

Iceland's largest geothermal mud pool is a little bit haunted and a little bit dangerous.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

Walk in the footsteps of the gods and straddle two tectonic plates.

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

Medicinal spa created from the mineral-rich runoff of a geothermal power plant

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

One of only two commuter aerial tramways in the United States.

Elevated freight railway turned wildly successful urban park.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

Elvis's own personal tropical hideaway.

A pair of giant roadside arrows are all that remains of a former Route 66 trading post.

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

Experience a charming 1930s version of "infotainment."

The world's longest known cave system.

A sign at the end of the Santa Monica Pier marks the traditional end of the legendary American highway.