The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

A tunnel once abandoned now thrives with graffiti art as an off-limits makeshift gallery.

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.

The oldest operating apothecary in the US has treated everyone from Thomas Edison to Mark Twain.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

Tucked in a nondescript downtown Brooklyn mall is a bar containing a remarkable turn of the century anatomical wax collection last seen in 1920s Berlin.

Home to the infamous "Typhoid Mary" and the worst loss of life in New York's history prior to September 11, 2001.

Nondescript elevator doors open to reveal a stunning, surreal world.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

The original toys that inspired the beloved children's stories are on display at the New York Public Library.

World's largest collection devoted to one fruit.

Along a California highway is a kind of Jurassic Park made of metal.

This desert oddity hides in plain sight thanks to a cartographic error and a desert explorer with a punny sense of humor.

A secluded hilltop monument marks the final resting place of Lucy, Presidio Park's beloved white deer.

One of the only known surviving coconut palm trees in the entire state.

If you are looking for a used Russian battery, Chinese Ham Radio or other electronic oddities this Flea Market is a good place to start.

This Pringle-shaped ledge makes for the perfect photo op.

The overgrown ruins of a once thriving World War I-era copper mine.

L. Frank Baum wrote part of the "Wizard of Oz" series in this wooden Victorian beach resort.

Alleyway plaque commemorating the death of a fictional character in The Maltese Falcon, not far from the author's home.

Gold Rush ship-turned-hotel buried underneath San Francisco's financial district.

A pair of mutilated bronze octopuses slump at the base of the monument honoring California's admission to the U.S.

A library built during San Francisco's pioneer times is a student's retreat, bibliophile's sanctuary, and chess player's delight.