This elaborate towering structure was once famed for its revolutionary height.

A daily replay of the experiment that proved the rotation of the Earth.

Yo, Adrian!

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

An atomic bomb-proof strongbox protects the U.S. Constitution from terrorists and thieves.

After a short-lived attempt to bring America in line with the rest of the world, this road was left in metric.

Quite simply the largest tree in the world (by volume).

The infamous Boston Mob ran rackets from an office here in the 1970s.

The first bell ever cast in Boston was cast by Paul Revere...and sounded terrible.

The nation's second-ever First Lady urged the founding fathers to "remember the ladies."

The statue of John Harvard isn't actually John Harvard—or even, technically, the founder of the school.

The tallest The Church of Jesus Christ of Latter-day Saints temple in the world soars above the Beltway.

This historic hotel invented the chocolate brownie.

This abandoned ironworks was once the most important military supplier in America.

These expertly crafted, scientifically accurate glass sea creatures were once an international phenomenon.

This giant monument of the RCA mascot is a beloved fixture in Albany, New York.

A bit of retro transportation flair preserved in the world's largest department store.

An ear-piercing buzzer calls lawmakers to a vote with a series of long and short rings to form coded messages.

Shoreline strewn with the remains of ghostly fallen trees.

This medieval village/restaurant perpetually celebrates the year 1376.

Rumor has it the hot dog stand was targeted by two Russian nuclear missiles.

High on a hill overlooking Los Angeles lives a world famous, high-power conical Tesla Coil.

A 1,100-ton train fell through the floor in 1953. Workers got it patched up in just 72 hours.

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.