A working model of the entire San Francisco Bay and much of the Sacramento River Delta, complete with regular tides that change every 14 minutes.

A huge musical instrument played by the ocean.

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

Visible below the waves are memorials to the city's Gold Rush dead.

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

Tiki luxury on Nob Hill.

Longtime headquarters of controversial boys' club for the world's wealthiest and most powerful.

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

In this century-old literary safehouse, print is alive and well.

This hidden rooftop garden in downtown London offers a quiet respite from a bustling city.

The only runway directly into the magic kingdom has been closed since 1972, but it still sings to you if you drive fast enough.

One of New York's best collections of pinball is hidden in a secret bar in the back of this laundromat.

An enormous, inside-out glass globe built in 1935.

A morbid secret lies hidden within the beautiful walls of the Boston Athenaeum.

A beautiful Victorian-era cemetery, complete with a miniature village.

Two thousand artifacts from around the world collected by one woman who loved to travel.

This upscale streetwear store is hidden behind a fake Snapple machine in the back of a deli.