The U.S. Navy's last diesel-electric submarine rests half-submerged in the middle of Portland.

Inside a humble hangar is some of the best roller derby the world has to offer.

A wild west land agreement was etched right onto this historic Idaho stone.

The decorations were inspired by an unlikely missing treasure.

Natural rock water slides hidden in the remote forests of northern Idaho.

This historic Idaho island is home to a strange timeshare museum, a homemade mini-golf course, and an outhouse named Aunt Fanny.

A railroad tunnel that, upon its completion, was considered one of the engineering marvels of the modern world.

The ruins of this Thomas-Jefferson-designed mansion have been left to crumble since the Christmas Day they burnt down.

The story behind the mysterious symbol painted in front of the historic university's famous Rotunda.

Edgar Allan Poe's old dorm is now a shrine to the author's legacy.

Anna Anderson spent most of her life claiming to be the lost Romanov child Anastasia.

An abandoned textile mill that is now home to art and concerts.

Thomas Jefferson's estate is home to hundreds of varieties of historic fruits and vegetables.

The only museum outside of Australia dedicated to exhibiting the artwork of Indigenous Australian artists.

The oldest surviving one-room schoolhouse in Montgomery County, Maryland.

These abandoned waterworks are crumbling into the Potomac River.

The span is crooked and made from two older recycled bridges.

Once a sewer culvert, this road tunnel now offers cyclists and pedestrians a subterranean stroll under the C&O Canal.

Largest Roman Catholic church in North America.

An Industrial Revolution-era public work that purified water using nothing but sand.

Enormous piles of historically significant stones, dumped by Congress in a forest, and abandoned for 60 years.

A super-sized promotional trick that is now a D.C. landmark.

The site of the climactic scene from the classic horror film is now a historic landmark.

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.