Bison, America's national mammal, are staging a slow comeback in Ohio's prairie parkland.

If you want to build a better mousetrap, first consult this small museum's massive collection of trapping tools.

A retro walk through the history of the tube.

Memorials and tributes scattered across the university grounds remember a famous national tragedy of the Nixon era.

Rainbow-hued in the summer and crystalline in the winter, this salty lake has inspired battles, temples, and plenty of awe.

A slab of sandstone covered with mysterious 1,000-year-old rock carvings from a vanished North American culture.

Rare recess caves fill this unbelievably beautiful Ohio park.

One of the last active volcanoes on the Eastern seaboard.

Spectacular mineral formations fill these caves, which have been used for everything from smoking meat to stashing illicit liquor.

This former fire tower found new life as a communications hub complete with a scenic overlook.

The first blast furnace in the United States that used coal and coke fuel instead of charcoal to make pig iron.

This beautiful stone arch bridge wasn't even expected to stand for one day, but people have been crossing it for centuries.

This Pennsylvania cave holds evidence of the oldest known inhabitants of North America.

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

One of the first Second Empire-style buildings constructed in North America.

This cannon dating to 1755 has stood guard at this suburban intersection since 1915.

This brick-lined pedestrian walkway was once a railway tunnel used during the Civil War.

This fort down the Potomac from Washington, D.C. was once the only defensive fort protecting the capital.

This twice-relocated "Usonian" home is among the smallest built by master architect Frank Lloyd Wright.

This museum explores the history of stickers and is home to RePEELed, an exhibit featuring sticker art from around the world.

The "birthplace of insulin," where Sir Frederick Banting realized the hormone could save the lives of Type 1 diabetics.

The ruins of a rehabilitation center for World War II vets can be found in the Westminster Ponds Conservation area.

A small museum houses a long, rich history of life and death on Lake Erie — from famous shipwrecks to rum smugglers.

More than 350 million years ago, western New York was covered in a vast sea. Today, you can dig up the remains of the plants and animals that lived there.