One of the smallest towns in the United States.

The same security that protects our nukes accidentally protected a gentle herd of antelope.

Miraculous tree that seems to sprout out of solid rock.

A beautiful geyser under environmental threat.

An apocalyptic seismic event creates a deadly chain reaction that ends with a 6-mile long lake developing within weeks.

Once a lonely sentinel on the edge of the Great Plains, this rebuilt trading fort offers a glimpse of life on the Santa Fe Trail.

The remains of an early 1900s dude ranch that operated until the 1970s.

This distinctive Crescent City tradition dates back to the days of horse-drawn carriages.

This dramatic rail curve was once the target of a failed Nazi attack.

The highest point in Tennessee, Clingmans Dome bears witness to the ravages of one type of insect.

This Great Plains museum pays tribute to both the prosperity and tragedy of the North American fur trade.

When an ancient supervolcano erupted, some of Nebraska's prehistoric animals were forever preserved in ash.

A Norwegian-born sculptor created these soaring guardian angels at the entrance to Hoover Dam.

This picturesque cliffside beacon no longer calls to sailors but shines once a year in honor of a famous shipwreck.

Minnesota's oldest and deepest mine is now an underground physics laboratory.

At this Minnesota state park you can easily wade across the source of the mighty Mississippi.

The only rotating bar in New Orleans has been slowly spinning since 1949.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

The only visible piece of San Francisco's most famous shipwreck.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

On the Fourth of July this area will transform into a Pompeii-like storm of falling embers and ash.

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

There’s a hidden military meme engraved on the World War II Memorial.