A throwback train ride transports passengers through one of the lesser-known national parks in the country.

The second building of its name to occupy this location might be the finest flatiron building in San Francisco.

The key to turning shifting dunes into the green oasis of Golden Gate Park.

Golden Gate Park's historic collection of plants.

Inside an old airplane hangar, friends and strangers alike play on a massive trampoline.

This turn of the century masterpiece has a mysterious goaty interloper.

This concrete tangle of square pipes has stood as a proud thorn in the city's side since the '70s.

The remains of a ruined mansion memorialize the 1906 earthquake.

San Francisco's urban bison herd has persisted in the face of extinction, development, and disease.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

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

A psychedelic labyrinth on the San Francisco bay.

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

This stunning home looks like it belongs in medieval Europe, not North Carolina.

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

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

Stockholm's deepest subway station is also a stunning ecological wonder.

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

A huge musical instrument played by the ocean.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

Only hotel where you can legally launder money.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.