The perfectly preserved underground rooms where Churchill plotted the war against Germany.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

A well-preserved sheepherding camp now lies in the heart of the Granite Chief Wilderness, in the high Sierra Nevada.

This little valley along Highway 1 is engulfed by thousands of lilies during the spring season.

A magical place that lets you play in and explore the world of Studio Ghibli.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

The world is full of swimming holes, but few compare to Samoa’s idyllic To Sua ocean trench.

A clear blue swimming hole with hidden caves, still unexplored.

The now-abandoned tunnels were built for the transcontinental railroad on the route where the first wagon train entered California.

Led Zeppelin wrote some of their most iconic songs at this little 18th-century Welsh cottage.

This isolated structure beckons adventurers with sublime views of the Faroe Islands.

The only theatre in the world constructed specifically for sound movement.

A modern mechanical planetary system, part of a 10,000 year clock.

These subterranean storage areas hold emergency water reserves.

Art in the form of a winding, man made crack in stone.

This print shop boasts one of the largest pinball arcades in San Francisco.

A free, public museum dedicated to the fascinating science of sight.

Gold Rush ship-turned-hotel buried underneath San Francisco's financial district.

A famous alternative culture epicenter and where Joplin serenaded young hippies.

Alleyway plaque commemorating the death of a fictional character in The Maltese Falcon, not far from the author's home.

A nondescript building that's been functioning as a speakeasy for nearly a century and a half.

A pair of slides and a tree-lined stair corridor have been an urban oasis for nearly 40 years.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

An artsy hidden staircase leads to breathtaking views of San Francisco.