This bright yellow relic is the final survivor of a short burst of seashell-shaped petrol pumps.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

NYC's legendary underground network for bovine transportation.

Hidden in an ordinary Midtown building is a one-room museum dedicated to the greatest escape artist.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

The site of the climactic scene from the classic horror film is now a historic landmark.

The final resting place of the Emperor of the United States and Protector of Mexico.

Hundreds of handmade critters fill this tiny window gallery in the heart of Portland's Alberta Arts District.

These old stone ruins in the Oregon wilderness were once bathrooms and are steeped in legends of murder.

This grand old 80-foot sequoia towers above the buildings in the city’s retail center.

An ice cream parlor chain that caters to vegans and pinball fans equally.

Recovered from the brink of extinction, at home in the Financial District.

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

This partially buried wreck is one of the most complete of its kind but is only revealed when the sea allows.

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

Gold Rush-era tombstones line the park's paths.

San Franciscans leave gifts and messages for the magical beings that live behind the tiny, mysterious door installed on a tree in Golden Gate Park.

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

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.

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

An essential stop before plundering, BYO Cutlass.