One of few lasting examples of the brief octagon craze that developed into folly.

A man-made island in scenic San Francisco Bay.

Golden Gate Park's historic collection of plants.

This private residence was the template for one of the most beloved television homes of all time.

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

Gold Rush-era tombstones line the park's paths.

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

The oldest burial ground in the city, final resting place of city founders, Ohlone natives and murderers alike.

A historic hotel that made a cameo in Hitchcock's classic film has no intention of letting guests forget its fame.

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

Staircase winds down the side of Telegraph Hill through gardens, wild parrots flying overhead.

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

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

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

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

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

A huge musical instrument played by the ocean.

Two plaques commemorate the site of Shakespeare's first theatre.

This one has sailed five times as far as Sir Francis Drake's famous ship.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

Eighty million natural history specimens call this gargantuan museum home.

This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.

An unusual round church in London with a Templar past.