Straight out of a nightmare, barcode-faced babies climb up and down Prague's television tower.

A gorgeous, Gaudí-esque stairway constructed in the city of Istanbul by a prominent Jewish family.

Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

A marvel of Byzantine engineering under the streets of Istanbul.

The ornate miniature mansions were built for Istanbul's feathered residents.

A meow-velous tribute to a beloved street cat, made famous on the internet.

The most metal church of all time was built in record time because of an international, pious pissing contest.

Byzantine emperors ruled, lived, and died in this 13th-century palace-turned-museum.

Climb a set of vertiginous stone steps to the top of this impressive ancient edifice.

The only Roman honorific column in Istanbul.

Turkish adventurer antiques in the heart of the Grand Bazaar.

1513 Turkish world map, full of European state secrets and snarky commentary.

Taking the subway here means doing so over a bridge located in the middle of an estuary.

This column celebrates Rome's victory over the Goths, and may be the oldest Roman monument in Istanbul.

No one is sure if the world's fourth-largest diamond had been found in a rubbish heap or was pawned by Napoleon's mom.

This crucial gathering spot along the "hippie trail" still displays old notes between traveling beatniks and backpackers.

A small etching on the white marble parapet was written in runic script by a Viking mercenary.

A fountain standing as a testament to a doomed alliance.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

Ancient serpentine sacrifice holder that has stood the test of time.

A tiny park in the middle of some big power politics.

A sixth-century Byzantine cistern hidden below a modern carpet store.

A historic and beautiful Art Nouveau chamber in a historic railway station.

This monumental mural crafted nearly 40 years ago is still in perfect condition.