It's safe—and permitted—to walk across these twin natural sandstone arches.

A preserved portion of an ancient Athens barrier is displayed in a hotel basement.

According to legend, this ancient column contains healing properties.

An often overlooked ancient site in downtown Athens with substantial history (and nature).

The ruins of an ancient fortification wall sit in front of and underneath this boutique hotel.

Take a self-guided tour through one of Colorado's most elevated mining districts.

These caves secretly held national treasures during World War II.

Only a few signs remain of the buried Colorado mining town that supplied the uranium for the first atomic bomb.

A small side chapel in Santa Fe's basilica is home to the oldest statute of the Virgin Mary in North America.

This giant pocket watch is the third iteration of a local landmark that has been standing just off the Santa Fe Plaza for over 100 years.

It takes a nine-mile hike to reach these hot springs, but weary hikers are rewarded with stunning views and a warm soak.

An abandoned sawmill from more than 134 years ago stands testament to the ambition of one man.

This sundial indicates the time based on where you stand within it.

Its history includes dinosaur fossils, cattle rustlers, Georgia O'Keeffe, and a mythical giant rattlesnake named Vivaron.

On the edge of the Valles Caldera National Preserve, these rock formations create an eerie landscape.

The 7,000-year-old calcium carbonate formation creates a magnificent natural bridge.

A strange sandstone formation in the middle of nowhere presents an interesting climbing opportunity.

One of Mexico's least-visited archaeological sites is tucked away inside a theme park.

A saloon and inn that served the Wild West's most iconic figures—and is still haunted by some of them today.

The site of the gruesome massacre—and maybe cannibalism—of five men, a tragedy that made Alferd Packer infamous.

These mid-century motels once housed the workers who built the Glen Canyon Dam.

Millions of numbers carved in glass represent the tattoos forced upon victims.

This nearly 200-year-old restaurant's history includes an exiled French prince, JFK, and a very hungry Daniel Webster.

This historic patch of real estate offers a glimpse of colonial Boston.