An amazing example of early-20th-century architecture, this church features marble transported from Utah.

The U.S. Navy’s preposterously detailed mini battleship took 77,000 hours to complete.

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

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

The fountains of the U.S. Navy Memorial are annually salted with water from the Seven Seas as part of a nautical ritual.

One of the largest artillery pieces in the world sits in a Washington D.C. parking lot.

A clone of a cloned tree that was so important it allegedly had its own guards.

A hoard of sky catalogs, astrophysical journals, even the works of Galileo and Copernicus.

A celebrity from the late Cretaceous period.

A nostalgic bibliographic gem.

People escaping slavery may have hidden inside a corpse vault.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

An incredibly well-preserved piece of ninth-century Viking poop.

The final resting place of England's most notorious bandit.

This sculpture marks the spot where one of the greatest Roman rulers was proclaimed emperor.

The little-known second castle that William the Conqueror built in York.

This medieval church tower has maintained its clockworks since the 16th century.

The castle still holds traces of the abandoned Roman fort it was built atop.

This pub was 238 years old when it decided to revamp its image: It started serving Thai food.

The commemorative stone column conceals a secret laboratory.

One of the shortest streets in York has an especially odd name.

Recently restored menagerie of Victorian-era beasts.

Don't be fooled by this fake medieval facade even if it is almost 300 years old.

Touching this 18th-century Scottish philosopher’s toe allegedly conjures good fortune.