One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

A tall karst islet popularized by 007.

The most playful of the life-sized statues that make up Singapore's "People of the River."

Singapore's landscaping project is home to 18 incredible Supertrees.

One of the most breathtaking railways in Europe also takes one of the steepest climbs, from fjord to mountain plateau.

Monuments don't get much more metal than these three giant viking swords planted in a Nordic hill.

Men in rubber-soled boots serve as your "brakes" on this toboggan ride Hemingway described as "exhilarating."

Lava stone structures possibly dating back to the 19th century may have been a stopping point for voyagers between ancient Egypt and the Mayan Civilization.

This unique rock formation is quite the local celebrity, although one day it may come crashing down.

According to the Guanches, the aboriginal people of the Canary Islands, the king of evil lives inside this volcano.

Two geological phenomena in one precarious locale: a towering stone window, and a deep blue void.

These temples are among the oldest free-standing stone buildings in the world.

Stone Age solar temple is aligned with the sun on each equinox and solstice.

An abandoned set from the 1980 film "Popeye," claimed and repurposed as a theme park by creative locals.

This huge pile of volcanic boulders hides a stunning network of secret grottoes.

The English graveyard of Mineral del Monte, a magical little piece of Cornwall in Mexico.

An ancient capital city that dates back 3,000 years old and harbors many surprises.

This daunting 1st century fortress was purportedly the site of one of the most dramatic revolts of the Jewish-Roman wars.

Ancient Egyptian relief, claimed to depict an electrical light.

One of its engravings is believed to be among the first representations of medical and surgical instruments.

The largest known Ancient Egyptian obelisk.

This ancient structure is widely thought to be the oldest intact pyramid in the world.

One of the most well-preserved temples of ancient Egypt.

These Egyptian statues have survived for 3,400 years and were an acoustic wonder of the ancient world.