Pilgrimage site for star-crossed lovers.

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

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

An "anarchical" no man's land, complete with garbage sculptures and a hobo-run "Landfillian Library."

The granddaddy of all tourist traps, built on ice water, jackalopes, and a giant dinosaur.

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

Olfactory delights in San Francisco's Botanical Gardens.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

The second oldest continuously operating bar in Louisiana.

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

A Wild West jailhouse that slid down the mountainside.

On the outskirts of a reborn ghost town, a decaying post office remembers the bad old days.

An urban laboratory.

Seemingly grown on some other world, these New Mexico rock formations look like a disused science fiction set.

A shop full of natural curiosities, carnivorous plants, and costumed taxidermied mice.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

Home to the largest urban bat colony in North America, estimated at 1.5 million bats.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

This old mining town, deep in the California desert, has a year-round population of one.

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

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

The world's second-largest sundial, made entirely out of stone.

Sacred Indian temple that’s all monkey business.