The largest collection of model trains in the world is actually run using full-size locomotive technology.

Hot springs monkey spa in the middle of Hell's Valley.

An abandoned whaling station on an active volcano offers hot springs in Antarctica, surrounded by ruined giants of industry.

Medicinal spa created with the discharge from a geothermal energy plant.

This geothermal hot spring hides beneath a slowly growing mineral dome.

This set of three large, volcanic hot springs is a favorite haunt for intrepid divers.

This set of hot springs also comes with fantastic views.

Take a dip in the world's largest mineral hot springs pool.

A geothermal pool in North Iceland that is said to be the bathing spot of the legendary Grettir the Strong.

This massive redwood tree has stood in Northern California for nearly 2,000 years.

A long strip of fossil-filled limestone makes up this natural bridge above a rushing stream.

This grove of ghostly cedars was killed in 1700 by an enormous tsunami, felt from the United States to Japan.

Thousand-year-old trees tower within one of the world's only inland temperate rainforests.

This gem from the industrial age helps visitors and residents alike traverse hilly Stockholm.

Rising from the sea like a stone monster.

Dance on a hand-hewn log floor padded with bouncy boxcar springs at a saloon built in 1883.

This medieval village/restaurant perpetually celebrates the year 1376.

This Cold War missile launch site has been abandoned for 40 years.

From overly ambitious (and eventually abandoned) atomic dream to bustling office park.

This former mining hub holds a surprising abundance of undisturbed relics from the Old West.

Towering basalt columns, a creation of fire and ice.

A reproduction of earth's many biomes.

See massive fossils that are over 200 million years old in northeastern Arizona.

Site of the greatest known waterfall that ever existed.