This cathedral hides a sculpted dog that determines your fate and an unexploded shell from World War II.

Massive galleon from a box-office bomb docked in Genoa.

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

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

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

This one has sailed five times as far as Sir Francis Drake's famous ship.

Ship-sized kinetic sculptural fantasy.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

After nearly 60 years, there's still a bear at Paddington Station looking for help.

Scattered throughout London are ancient remnants of the city's former bounding wall.

Eighty million natural history specimens call this gargantuan museum home.

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

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

This whimsical group of statues is a favorite of children who love to climb all over Lewis Carroll's beloved characters.

Built hundreds of years ago this downtown iron barrier once protected a much despised king.

The New York hotel where tragic visionary Nikola Tesla spent his final hours, destitute and alone but for the pigeons.

A bit of retro transportation flair preserved in the world's largest department store.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

A dark patch of the ceiling at Grand Central Terminal which was not restored is still stained brown by tobacco.

One of the last few places in Manhattan that employed a pneumatic systemic keeps it on display.

An artist's cute bronze subway sculptures belie his violent artistic past.

Elevated freight railway turned wildly successful urban park.

The quirky gift from West Berlin for the 1968 World's Fair still stands in Hemisfair Park.