A psychedelic labyrinth on the San Francisco bay.

A huge musical instrument played by the ocean.

A promotional sun clock on the site of San Francisco's great raceway.

The stones that traveled from Spain to eventually become a holy place for San Francisco's nature worshippers.

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

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

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

A small, but award-winning beach known for its literally spotless reputation.

A mecca for India's Jains.

A single tree's 2,800 aerial roots give the appearance of a complete forest.

Modest by day, illuminated majestically at sunset.

A blooming house of worship for the masses.

An extraordinary "City of Caves" carved from solid stone.

More than half of this Indian palace is drowned but it looks all the more spectacular for it.

The remains of what was, not so long ago, the world's largest city.

Thousands of exquisitely carved stone water storage wells, hundreds of stone steps fill this exquisite medieval stepwell.

An imperial fortress city that incorporated cultural elements from the entire Mughal empire, only to be abandoned the year it was finished.

Famously misunderstood wonder of the ancient world

A battle between nature and architecture in the Cambodian jungle.

A shrine contains nearly 200 statues of the Buddhist deity Jizo, dressed in bibs by parents who have lost a child.

Hanging over one of Japan's "hidden valleys," these vine bridges must be remade every three years.