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

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

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

A favorite haunt of dinosaur loving children and hallucinogen loving hippies alike.

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

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

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

Olfactory delights in San Francisco's Botanical Gardens.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

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

Its buzzing collection honors vibrator history.

A winding path built in secret on the edge of the continent.

A psychedelic labyrinth on the San Francisco bay.

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

A huge musical instrument played by the ocean.

Dolphins, ancient clams and hundreds of waterfalls make this one of the world's top tourist destinations.

The glacier tucked within a New Zealand rainforest.

A glacier pocked with ice caves and surrounded by rainforests.

The ruins of New Zealand's largest classical-style church.

This strange geological landscape erupts with sudden bursts of water.

Built over an abandoned train yard, this hidden gem is full of winding paths and offers gorgeous views of Sydney Harbour.

This historic observatory contains the world's oldest refracting lens telescope.

Come for the flowers, stay for the bats!

This trio of Australian rock spires may have inspired aboriginal legend or just modern tourism.