Olfactory delights in San Francisco's Botanical Gardens.

San Francisco's first World's Fair, dedicated to the wonders of California.

San Francisco’s condensed garden of incredible plant growth.

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

One part antique store, one part curiosities hodge-podge.

A monument to the love people have for their pets.

Famously misunderstood wonder of the ancient world

Besieged by war, this castle ruin has crumbled into a peaceful picnic spot.

This hilarious English intersection is an automotive whirlpool.

Europe's largest prehistoric mound – burial site of a legendary king?

The largest stone circle in the world has ended up bringing up more questions than it has answered.

The ancient latrines of the Greeks, in all their public glory.

Major tourist destination known for its bubbling mud-pools and hot thermal springs.

Erotic art covers the walls of the largest ancient pleasure palace.

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

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

An elaborate gift from Claus Spreckels is now a piece of San Francisco history.

A masterpiece in Golden Gate Park by virtue of the artist’s debt.

Golden Gate Park's historic collection of plants.

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

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

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

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

An overlooked and unassuming engineering marvel.