A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

Museum celebrating the history of computers, especially their role in codebreaking.

An extraordinary library and archive dedicated to the history of the Arctic and Antarctic poles.

Steadily reminding Czechia of its past.

This Prague museum collects brutalist relics and memories from the country's former Soviet rule.

This former Norwegian sailor's church is slowly being taken over by ramshackle robot musicians.

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

A marvel of Byzantine engineering under the streets of Istanbul.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

A church of bones, decorated with 40,000 human skeletons.

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

Macabre astrological automaton clock dating to the late 1400s.

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

Four cars from the old system were once on display, but were removed in 2014.

A decommissioned military complex that's now a modern industrial park.

Ride the subways of yesteryear.

In the middle of downtown Brooklyn lies a 165 year old secret hidden right below the surface (closed to the public indefinitely).

This innocent-looking townhome is actually a subway exit.