One of the most scenic stretches of road in America winds between some of the country's oldest trees.

Quite simply the largest tree in the world (by volume).

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

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

Towering basalt columns, a creation of fire and ice.

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

Get lost in this haunting fairytale art walk through a man-made eucalyptus grove.

A trash dump made beautiful by nature's power.

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

Under the right circumstances, this waterfall in Yosemite briefly turns a luminescent fiery orange.

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

A 140-year-old castle with underground caves hidden in San Francisco.

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

A psychedelic labyrinth on the San Francisco bay.

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

A huge musical instrument played by the ocean.

One of the largest ochre quarries in the world, hidden in a limestone landscape.

A Spanish forest is filled with mysterious stone carvings.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Remnants of the rich history of fish salting in this ancient Mediterranean port town.

Two 2,500-year-old Phoenician boats found on the coast of Spain, giving incredible insight into the ancient maritime traders.

This cemetery features modernist statues as strange as its name.

An impressive display of ships and artifacts from the ancient Mediterranean maritime trade.

This magical space partly designed by Antoni Gaudi is one of the best examples of romantic gardening in the Mediterranean.