Fossilized sea bottom and lime quarry.

It wouldn't be long after purchasing this farm, Brown would lead his siege on Harper's Ferry.

A former infectious disease laboratory chronicles how tuberculosis shaped a village nestled in the Adirondacks.

It's a repurposed treasure trove of history, located just an hour away from Acadia National Park.

The highest point in Maine is a grand gift to the state citizens that also happens to be one end of the Appalachian Trail.

The “Grand Canyon of Maine” is a three-mile gorge full of striking geological features.

Long hidden under grime, the politically radical murals of a little known Yugoslavian master are finally getting their due.

This controversial reel is an artifact of the largest fish processing plant in the country, and a symbol of Delaware's integration.

The home and studio of a visionary woodworker now stands as a museum and example of his artistic genius.

The largest university building in the West is a gothic masterpiece containing dozens of theme rooms based on different countries.

There aren't too many operational funiculars around, but Pittsburgh has two!

The oldest farmer's market in America is so ancient it was approved by the King of England.

Dr Barnes' $25 billion private collection of art and arboretum.

Eccentric concrete mansion and museum designed and built by hand from the inside out.

The oldest surviving botanic garden in the United States.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

This lush forest valley was once mined for lumber to the extent that it was once nicknamed "The Pennsylvania Desert."

This unique creation was made by the largest manufacturer of Christmas bulbs in 1946 to honor those returning from World War II.

This strange, big-tailed beast became a Pennsylvania town's unofficial mascot.

A tree that grows parallel to the ground was declared Brooklyn's "crowning curio" by the poet who saved it.

This elaborate tunnel is the first structure composed of cast concrete in the United States.

Not to be confused with the iconic New York City skyscraper, this Chicago building is a vibrant hub for artists.

This memorial plaque remembers a strangely shallow maritime disaster known as "Chicago's Titanic."

The 606 is a decade in the making.