This 11th-century castle sits so low you can't see it behind the surrounding buildings.

An unassuming rod in the Netherlands was once the old standard unit of length for the entire Dutch empire.

A memorial commemorating the man whose name became synonymous with taking a picture in the Netherlands.

A trio of red, white, and blue stones embedded in the streets of Leiden are markers of medieval territory and law.

See 150 million-year-old dinosaur tracks and bones dating back to the Jurassic period.

Drift through decades of high desert music history at this funky hometown museum.

This museum offers an actual time machine back through Colorado's past.

The world's largest sticker ball weighs in at a mighty 231 pounds.

Hans Christian Andersen for the postmodern world.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

The design of this beautifully crafted building was inspired by Norwegian glaciers.

This floating sculpture of ice is a poignant reminder of nature's power.

A dramatic, 360-degree recreation of Pickett's Charge in the Civil War.

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

Graffiti from the 16th and 17th centuries cover the walls of this part of the Tower of London.

The United States’s oldest funicular railway glides up and down a steep Pittsburgh street.

Sections of the iconic limestone columns have been left uncleaned as a reminder of the city's polluted past.

A model of a dinosaur that was named for Andrew Carnegie stands outside the museum that also bears his name.

The largest university building in the West is a gothic masterpiece containing dozens of theme rooms based on different countries.

A portion of the old Pirates stadium over which a defining home run once flew still stands even after the rest of the stadium was torn down.

The last remnants of Fort Pitt also hold the distinction of being the oldest structure west of the Allegheny Mountains.

Pittsburgh’s largest and most detailed model train display began as one WWI veteran’s hobby.

This permanent exhibition celebrates the finest of our heartless automatons both real and fictional.

When oil was discovered just outside of Pittsburgh, the city became home to this regional stock market.