This historic castle was already in ruins by the 13th century.

Deliberately hidden for centuries, the magnificent Saadian Tombs were eventually uncovered in 1917.

The largest madrasa in Morocco once housed more than 900 students within its exquisite walls.

It took 40 years to build this Eden-like garden in Marrakech, later restored by Yves Saint-Laurent.

An underground mansion with fruit-bearing trees and grapes growing beneath the surface of central California.

A hotel and restaurant serving as the mecca of kitsch.

Olfactory delights in San Francisco's Botanical Gardens.

The trunks of 3,000 year-old trees lurk beneath the surface of this crystal clear lake in Oregon.

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

No one knows how this Pacific Northwest spruce tree came to have so many trunks.

This geothermal hot spring hides beneath a slowly growing mineral dome.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

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

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

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

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.

Wondrous sandstone hoodoos where Native Americans collected clay for pottery, 9,000 years ago.

On the Oregon coast there is a natural hole that seems to be draining the sea.

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.

The one-stop shop for all of your superhero (or evil arch-nemesis) needs.

Order scoops of pandan, lychee, and black sesame at this family-run institution.

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

One of only two commuter aerial tramways in the United States.