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

Concrete strongholds stand guard over the Golden Gate.

A working model of the entire San Francisco Bay and much of the Sacramento River Delta, complete with regular tides that change every 14 minutes.

Home to drunken tower-climbing goats... seriously.

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

This homegrown adoption center offers a wonderland of feline companionship.

Beautiful Gothic-inspired lighthouse stands out among the run-of-the-mill striped fare on Bodies Island.

The most accurate timepiece in the world.

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

Washington's iconic carousel has a nice piece of Civil Rights history.

The most decorated dog of World War I is preserved in the Smithsonian.

A heroic pigeon that, through a barrage of gunfire, delivered a message that saved over 100 lives in World War I.

The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

Look closely and you’ll notice that the color changes a third of the way up the tower.

One of the world's largest model railroads is a mind-boggling achievement.

One of New Jersey's oldest surviving buildings still bears the mark of our former British overlords.

The world’s first penitentiary, meant to be humane, drove men insane.

An Irish Memorial commemorating those who perished due to potato blight.

World War II-era bunkers are hidden under the beaches of this picturesque park, which is still scattered with wartime watchtowers.

The Dover International Speedway is home to a towering, concrete-skinned, racecar-hungry behemoth.

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

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!