Enormous lake at the bottom of a unique cave system.

One person's lost luggage is another person's treasure.

Knoxville’s architectural icon was the symbol of the 1982 World’s Fair, even catching the googly eye of Bart Simpson.

This marine reptile was discovered by one of the 19th century's greatest fossil hunters.

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.

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

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

Eighty million natural history specimens call this gargantuan museum home.

Rare recess caves fill this unbelievably beautiful Ohio park.

A statue of the legendary Celtic warrior queen who fought the Roman invaders stands in one of the cities she once destroyed.

A take-out restaurant that only serves cuisine from countries with which the United States is in conflict.

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

There aren't too many operational funiculars around, but Pittsburgh has two!

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

A monument to a Native American leader who was known for never breaking a promise and met his end after signing a deal with white settlers.

The world's longest known cave system.

Amazing taxidermy dioramas from the 1960s in a cement building meant to look like an ice cave.

This steamer is known as "The ship that built Cleveland."

Bison, America's national mammal, are staging a slow comeback in Ohio's prairie parkland.

The world's tallest doric column is this Ohio monument to a naval victory in the War of 1812.

This whimsical campus lawn is dotted with large sculpted numbers and hidden mathematical formulas.

A single handprint, which, according to Ohio State University legend, cannot be scrubbed off.

Cleveland's giant "free" stamp is a nod to the Civil War, but was misinterpreted for years.

Landmark dedicated to the plight of the American Indian in the 21st century.