Peace Park and the Atomic Bomb Dome.

Where Cusack's record store from the film "High Fidelity" was located.

World's second largest particle accelerator, where nature reveals its secrets.

Twenty-seven massive radio antennas on the high plains of New Mexico search for life on other planets.

Started nearly 100 years ago, this science experiment just keeps on going, ever so slowly.

The world's third-largest scale model of the planets.

Huge concrete structures designed as an early warning system for Britain to detect enemy aircraft.

Rebuilt remains of a temple to Roman god Mithras.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

A 30-year-old Sycamore tree grown from a seed taken to the moon and back.

Display that gathers the basic elements of the universe in one convenient location.

Large Hadron Collider and the Birthplace of World Wide Web.

A neutrino detector built into the largest man-made underground cavity in the world.

An encyclopedic collection of mammal penises.

Robots, lasers, and whoopee cushions, oh my!

A large circus museum with summer performances.

More than 5,000 contemporary and "historic" mustards from around the world.

Race through the maze, get your name on the sign.

The clock that sets them all.

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

A sealed test tube said to hold Thomas Edison's dying breath was given to the inventor's friend and mentee, Henry Ford.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

America's post-nuclear-attack chambers of Congress.

Ruins of a German Castle on top of a towering stone pillar.