Narrowest house in Boston.

Inspiring Herman Melville and Henry David Thoreau, Mount Greylock in western Massachusetts is the highest point in the state at 3,491 feet above sea level.

Locals purchased this abandoned quarry in order to make sure it continues to be overgrown.

Books you don’t need in a place you can’t find.

This structure among the trees was the result of divine inspiration.

Once decrepit and slated for demolition, now one of the longest pedestrian bridges in the world.

An abandoned theme park with a strange and tumultuous past.

Prehistoric animals decorate this popular outdoor park.

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.

A replica of a 7th-century church hides in plain sight in the middle of the concrete jungle.

Twenty-three trees, each paired with a basalt stone, line a street in Chelsea, continuing an urban project started by German Fluxus artist Joseph Beuys.

A plaque immortalizes the spot where the early American spy said his famous last words: "I only regret that I have but one life to lose for my country."

This simple Manhattan salt house is artfully shaped... well, like a giant granule of salt.

This natural wonder drops 16 stories straight down through rare flora and streaming waterfalls.

Labor provided by Great Depression-era programs restored these 25,000 acres in Tennessee.

Visit this playground of waterfalls, caves and sinkholes.

The small cave that housed Tennessee's "first citizen."

At 135 years old and counting, this historic print shop is heaven for poster nerds and music buffs.

Over fifty whirling pools left by the glacial age.

Three prestigious academic collections come together to create a world-class natural history museum.

This small section of the Sleepy Hollow Cemetery is rotten with famous authors' graves.

This former Masonic hall has been turned into an art project that uses even more metaphysical iconography.

Memorial of the Salem witchcraft hysteria in the town of Danvers, where it all began.

A New England ghost town features a trail of boulders etched with intriguing life lessons.