During prohibition, corrupt city officials ran drinking dens under the streets of Downtown Los Angeles.

You'd never know the houses at 23-24 Leinster Gardens were fakes—until you see the train tracks on the other side.

Home of one of history's most famous cartoonists just as he left it.

The Columbia Road Flower Market is now open every Sunday, rain or shine.

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.

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

Public access to clean drinking water was an instant hit among the masses.

This hidden rooftop garden in downtown London offers a quiet respite from a bustling city.

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

This legendary stone is of unknown origin, and throughout history has been a literal touchstone for British leaders.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

Remnants of a Victorian garden feature sitting in public woodland.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

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

Hear the quietest sound from across the dome.

The signs of a long buried road can still be found hidden beneath a London sewer grate.

The oldest house in Chicago certainly doesn't look the part and there are some who say it doesn't deserve its title either.

All of Chicago's wood-paved streets are long gone but two alleys remain.

The twin towers in this Chicago fountain use 50 foot tall video screens to spit on people.

Former meatpacking facility turned vertical farm and sustainable business complex.

Pizza with a side of fine art.

What's left of the ruins of the 1893 Columbian Exhibition, or World's Fair, also known as the White City.

A hollow cement depiction of time's inexorable effect on the human body.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.