Venice's "Island of the Mad."

This community on a small Venetian island has taken to painting their houses in bright neon hues.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

The ritual has been performed uninterrupted for nearly 700 years.

An architectural oddity hides in plain sight on this iconic London bridge.

"We gonna rock down to Electric Avenue, and then we'll take it higher..."

A labyrinth hides in plain sight at each of the city's 270 Tube stations.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

A subterranean ice warehouse that has lain hidden beneath central London for over a century is now open to the public.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

Also known as the Blue Church, the building was consecrated to the daughter of Andrew II.

A line of disused military bunkers built to defend against Nazi invasion lies hidden on the outskirts of the city.

The largest fountain in Bratislava.

A cableway for car transport.

This spaceship sculpture in the middle of the Slovakian capital looks like it just crash-landed.

Once a train station along the Great Eastern Railway this vibrant coffee shop and bar is where members of London’s creative class mingle.

Just outside of Nairobi lies a large estate surrounded by endangered Rothschild giraffes, who have been fed from the window by Mick Jagger and Walter Cronkite.

There's an exclusive Beefeaters pub hidden in the Tower of London.

Originally built for London’s cab drivers, this bright green hut now serves anyone a hot drink or meal.

This East End pub gained notoriety as the site where gangster Ronnie Kray publicly shot a rival.

This pub built its reputation pouring post-shift pints for employees of the cemetery with which it shares a wall.

Drink your espresso at a Victorian-era urinal in this underground-restroom-turned-coffee-bar.

Drink wine handed out through a window as part of an age-old tradition.

The first modernist church in Europe.