Sculptor Antony Gormley used chaos theory and fractal growth to design his tallest creation.

The oldest colonial fortress in the Americas was once the home and later prison of Christopher Columbus.

After Christopher Columbus died, his son built a fancy house to rule from.

London's only public statue of the much-married monarch adorns the gate to St Bartholomew’s Hospital.

A plaque hangs near the execution place of the Scottish Independence leader famously depicted in "Braveheart."

This pump on the bad side of Victorian London betrayed a horrifying revelation about the water supply.

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

19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.

Buried for centuries, this hidden cellar is all that remains of London's medieval Whitefriars Monastery.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

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

The last four extravagant street signs of London's historic banking street.

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

The second-largest gold nugget in existence, displayed in a Las Vegas casino conveniently named the Golden Nugget.

An exotic wildlife habitat right off The Strip.

Back in 1952, you could get a mushroom cloud chaser with your atomic cocktail.

The bullet-riddled wall from the St. Valentine's Day Massacre, bloodstains enhanced for your viewing pleasure.

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

This incredible collection of vintage pinball machines can be played at 25 cents a pop.

Flashy signs from Las Vegas’s past find their final resting place at this unusual graveyard.

Be on the lookout for the symbolic insect all over the city.

The small bright red pillar survived the 1996 Manchester bombing virtually unscathed.

The only electricity pylon under whose legs you can go by boat.