A 1,100-ton train fell through the floor in 1953. Workers got it patched up in just 72 hours.

Look closely and you’ll notice that the color changes a third of the way up the tower.

Perhaps the most scandalous statue of America's first president.

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

The walls of the iconic dome are hollow and have a secret stairway.

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

Stalinist skyscraper built with help of cryotechnology.

One of the world's tallest statues is also one of its most hated.

Gargantuan home of Russian science.

This massive monument honors the first human in space.

The tallest hotel in Europe.

Moscow's most popular cemetery includes the graves of numerous cosmonauts.

Former headquarters of the KGB.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

This building holds the embalmed remains of the leader of the Bolshevik Revolution.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

Climb to the top of its spiral spire for spectacular views of Copenhagen.

The childhood home of the Sultan of Swat is just a line drive away from Oriole Park at Camden Yards.

Baltimore's classic clock tower was once topped by a rotating, 20-ton medicine bottle.

This bug-eyed water wheel uses the power of the Sun to clean up Baltimore Harbor.

The trials and tribulations of marking Poe's grave.

At 238 feet above the bottom of a gorge this span is known as the biggest thrill on the road to McCarthy.

Running under an entire mountain, the longest highway tunnel in North America is kept fresh using portal fans and jet fans.