Used as a military post in three different engagements, this fort has remained incomplete and unfired upon for nearly 200 years.

Visit a fourth-generation farm and museum dedicated to everyone's favorite fungi.

This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

A blend of art, antiquities, and Americana fill this museum, surrounded by whimsical, enchanting gardens.

A pride of the state, this working museum crafts pottery mosaics in the style of Pennsylvania's earliest European settlers.

The mansion home of author Edith Wharton.

Two thousand artifacts from around the world collected by one woman who loved to travel.

This bridge was the birthplace of a unit of measurement based on a fraternity joke.

An enormous, inside-out glass globe built in 1935.

This impressive Boston holy house is the American mecca for Christian scientists.

Statue in Salem of the woman who starred as the witch Samantha in the sitcom "Bewitched."

One of 100 “Whaling Wall" murals painted in 13 different countries by a renowned marine life artist.

A crumbling hospital from the 1850s on Roosevelt Island.

One of only two commuter aerial tramways in the United States.

Elevated freight railway turned wildly successful urban park.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

The largest clock face in the United States is twice the size of Big Ben and infinitely more ad-sponsored.

The United States’s oldest funicular railway glides up and down a steep Pittsburgh street.

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

This giant monument of the RCA mascot is a beloved fixture in Albany, New York.

The original Uncle Sam was actually a New York meatpacker who is buried under this historic grave.

A 13,000-year-old mastodon skeleton was found during the construction of a 19th-century New York mill.

A hamlet full of permanent Christmas spirit holds one of the earliest theme parks in the United States.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.