The world's largest historic armory was established by independent citizens to defend themselves from the wars of larger forces.

The shell of a medieval fortress offers commanding views of the area it once protected.

Bizarrely-painted church designed by a controversial artist.

A vast necropolis where you'll find the elaborate mausoleums of Argentinian tango stars.

Museum housed in underground tunnels that date back to Buenos Aires's earliest settlements.

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

The first declared National Monument in the United States.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

This historic building provides a powerful glimpse into the lives of Japanese Americans forced to relocate during World War II.

The fifth-longest natural arch in the world, and the longest outside China.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

The hotel where Martin Luther King Jr. was shot is now a museum dedicated to his work.

This Memphis recording studio launched the careers of Jerry Lee Lewis, Johnny Cash, and Elvis Presley.

This replica of the Greek structure is in the heart of Nashville.

Hidden behind Lincoln's head is a 70-foot-long chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

The oldest still-operating tavern in the United States was once owned by a pirate.

This church in Pittsburgh is home to the largest collection of religious relics in North America.

In the early 1800s, surgery was also a show.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

The magic's in the hole!

10,000 flowered plants bloom in the City of Roses.

This tiny church near Sleepy Hollow contains Henri Matisse's last work, a rose window, and nine windows by Marc Chagall.

The real-life site of Ichabod Crane's infamous gourd attack.