This magnificent natural sandstone bridge is one of the largest in the world and is an iconic symbol for Lake Powell.

This hidden gem in Arizona is truly worth the rugged journey.

This massive library holds what was once the largest book collection in the world.

At this gas station in the middle of the desert, a convenience store has been carved directly into the rock.

A gruesome combat between a hunter and a furious momma bear.

Although it also features red, orange, and variegated cliffs of Navajo Sandstone, this state park is often overshadowed by its more famous neighbor.

This bridge over D.C.'s Rock Creek Park is sometimes called the "Buffalo Bridge" because of its four buffalo sculptures, which were cast from a single piece of bronze.

Guns that have been defending San Francisco since 1904.

See four top-secret US spy aircraft of the Cold War era, including the legendary SR-71 Blackbird and the A-12 Oxcart.

The spectacular and eerie moss-covered grave site of 19th-century Belgian merchant.

Big gun installations, built over a massive cemetery, now abandoned & hidden in trees.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

A hidden gem, named after a San Franciscan icon, offers spectacular views of the Pacific Ocean.

A converted hangar displays dozens of helicopters, from a famous 1943 rescue chopper to several autogyros.

Housed in a stunning Victorian building, this museum has the largest exhibition of knives, blades, penknives, and scissors in Spain.

Luxembourg's first beer museum honors the Grand Duchy's contributions to the art and science of beer-production.

A model of a dinosaur that was named for Andrew Carnegie stands outside the museum that also bears his name.

One man's prolific, decade-long quest to turn trash into artistic treasure.

Where the alchemists dream of transmuting base metal into gold was actually achieved.

This massive oak tree has ties to the first native tribes of the region and the founders of Texas.

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

Turning night into day in Victorian-era Austin to thwart a serial killer.

This 36-foot-tall bronze Lady Liberty holds a real flaming torch.

On a corner of the Ardmeanach peninsula on the Isle of Mull, a 50 million-year-old fossil tree hides in the coastal cliffs.