The world's smallest park was dedicated in 1948 as the only colony for leprechauns west of Ireland.

The longest continuous lava tube in Oregon.

The second largest waterfall by volume in the U.S., Willamette Falls is outdone only by Niagara in the amount of water that is pushed northward.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

The highest point in Washington state is a volcano covered in glaciers.

The longest continuous underwater road in North America was built at the insistence of Franklin Roosevelt.

Pulled from the rubble of one of the worst modern tragedies, a steel crossbeam became a symbol of hope for New Yorkers.

One of many reminders of Tesla's scientific contributions overlooks the falls which inspired him.

This sandstone gorge in New York State's Adirondack Mountains is home to waterfalls, flumes, and more.

A popular European tradition makes its way to the states on one of America's most famous bridges.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

Elevated freight railway turned wildly successful urban park.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

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

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

The United States Capitol's former columns still stand.

This giant iron playfully pays tribute to an early 20th-century architectural trend.

Who needs fancy modern water slides when this giant North Carolina rock works just as well?

South Carolina's last remaining slavery auction house is now a museum devoted to its own tragic history.

One of the oldest living oak trees in the Southeast.

This funicular railway rumbles along for a mile up the nearly vertical face of Chattanooga’s Lookout Mountain.

A recreation of the doomed ocean liner in the middle of the Smoky Mountains.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.