A 19th century library favored by Edgar Allan Poe and H.P. Lovecraft, known by locals as "the Ath."

One of the oldest libraries in England, and one of the last of the great medieval chained collections.

The fossilized remains of ancient California redwoods.

California's own medieval Italian castle, authentic down to the 300-year-old iron maiden in the dungeon.

A short hike into the mountainside forest reveals a decaying 1890s town.

An abandoned 18th century manse looks like something out of an Indiana Jones movie.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

This unassuming home was once “grand central station” for the Underground Railroad.

A plaque marks a former safe house on the secret route, now hidden next to a McDonald's.

A 19th century family buried their dead among the pines, beneath gravestones styled after ancient Scottish cairns.

These mouldering mansion ruins remember a time when the Catskills were nothing but luxury.

The final resting place and once home of the Bandit Queen of the West.

This once luxurious Catskills resort is now a haunting ruin.

The convergence of two currents makes this a surprisingly pleasant getaway in the Arctic Circle.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

A once-luxurious, now abandoned hotel in the Italian Alps.

A ruined mansion hidden in the woods of the Hudson Valley, home of a tragically doomed romance.

Ruins of the elaborate house where the enigmatic costume designer threw glamorous parties for New York's theatrical elite.

Mausoleums, astronomy, and animatronic dinosaurs at this memorial to an assassinated American president.

Petrified footprints of one of the very first vertebrates to walk on land.

Fossilized sea bottom and lime quarry.

The only diamond mine in the world where you can keep what you find.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

An ever-evolving wall of graffiti art off East Liberty Street.