Once America’s most beautiful army base, this abandoned military fort on the coast of Monterey Bay has been left to the elements.

The California capital city once stood 10 feet lower than it does today.

Hidden beneath a lake for decades, this brutalist mine has now emerged from beneath the receding waters.

Barely visible foundations remain where Stow Lake’s “observatory” once welcomed visitors.

From the sky, a kaleidoscope of color brightens the grey landscape of the San Francisco Bay.

The unbelievably opulent home built for an infamous newspaperman.

A burnt orange monolithic dome structure perched on a hillside near Interstate 280.

These delicate buggers are some of the rarest fossils that have bubbled up from the Tar Pits.

Rodin's famous depiction of Dante's 'Inferno', amidst a sculpture garden of many of his other works.

San Francisco's newly reopened hands-on science museum.

A "gravitational anomaly" located in the redwood forests just outside of Santa Cruz, California.

Towering basalt columns, a creation of fire and ice.

One of the final grand railway depot hotel complexes is slowly being restored to its former glory.

Walk through the actual strap iron cells and solitary chambers of Arizona Territory’s first prison.

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

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

Population: 1.

An architect's childhood fantasy treehouse made real.

A 90-foot-tall psychedelic "tree" on the side of the highway has baffled passersby for decades.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

Experience a charming 1930s version of "infotainment."

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

The famous abolitionist’s preserved estate is one of Washington's finest monuments to its great Black citizens.

A famous hotel houses an impression collection of mini dioramas and giant doll houses.