Small church on top of a huge rock column.

This neon lit Georgian cave claims to hold the boulder Prometheus was chained to.

A literally moving statue of stacked metal giants just continually trying (and failing) to find love.

Tower with a double-helix spiral, adorned with letters of the Georgian alphabet.

The first skyscraper to include a Ferris wheel built into the facade.

Underground monastery and fortress.

Ancient rock-hewn town that witnessed key events of Georgian history.

A museum glorifying the life of Stalin, located in the city of his birth.

The charmingly disheveled clock tower of Tbilisi's puppet theater.

Luxury hotel turned into a refugee camp, then turned back into a luxury hotel.

The largest of London's subterranean rivers and once a mad, bad center of London life.

A friendly pub with a sordid past in cock fighting.

London's smallest police station is barely the size of a phone booth.

Several plaster noses are hidden in plain sight around London's Soho neighborhood.

A statue of the original Pearly King is hidden in a church's crypt.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

Giant, friendly pelicans in Central London, the most unlikely of places.

There’s a secret bunker inside the Brooklyn Bridge, but the city won’t say where.

The very first subway station in New York City is beautiful, decked out in chandeliers, and ... abandoned?

Hidden in plain sight on a pair of Manhattan subway tunnels are a pair of public instruments that sing to each other.

Gang fights don't just happen on the streets, they happen under them too.

Currently housing a corporate bank branch this building at the southern tip of Manhattan was once the gateway to luxury vacationing.

This chapel on a cliff is renowned for its healing powers and was founded on the site of a supposed divine intervention.

A hyper-luxurious, 12,000- square foot home might be buried beneath Queens, still waiting to protect you from nuclear missiles.