The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

The world's largest Holstein cow.

Golden Gate Park's historic collection of plants.

A hidden subterranean installation offers a view of the sky.

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

A wild west cemetery in Tombstone, Arizona, provides a window into the Old West.

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

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

This downtown Dallas art installation is always on the lookout.

Two massive and unstable sinkholes are yearning to unite, and their consummation could be catastrophic.

Home to the largest urban bat colony in North America, estimated at 1.5 million bats.

Built on the remains of one the Incas’ most important gathering spots, this square keeps the spirit of a fallen empire alive.

Situated on a sacred Inca site, this 16th-century cathedral took nearly 100 years to build.

The little bear in the "funny kind of hat" has made his way from London back to Peru.

With nearly double the depth of the Grand Canyon, this Peruvian canyon is one of the deepest in the world.

The stones of this Incan wall complex fit together so well you couldn't fit a piece of paper between some of them.

Preserved Inca city and site of the last Inca stronghold against the Spanish conquistadors.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

Buenos Aires' city of the dead contains some very famous remains, including Eva Perón.

One of the few surviving examples of Victorian-era public toilets now houses a small homestay.

The southernmost point in the United States is a beautiful place to look at but a deadly place to wade in.

This former luxury resort in Kaua'i is now an abandoned relic.

These picturesque Hawaiian falls are home to a rare species of fish that uses a special sucker to climb up cliffs.