Even Henry David Thoreau found this glacial pothole irresistible.

400 million-year old limestone caverns nestled in the Ozarks served as shelter and a hideout for cultures throughout North American history.

Tour the world's largest deep-hole dimension granite quarry, where you can view the plant where gravestones are made and roll a ball down the outdoor granite bowling alley.

The highest peak in the state of Vermont has some interesting features.

This sandstone gorge in New York State's Adirondack Mountains is home to waterfalls, flumes, and more.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

A massive Montreal stadium that has seen nothing but trouble since its inception.

This 1967 experiment in modular architecture was designed to be a new model for urban living.

A grand Gothic Revival basilica with stained glass depictions of Montreal's religious history has only one soul resting in its crypt.

Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

A wall of chewing gum moonlights as collective art.

A bit of retro transportation flair preserved in the world's largest department store.

Spinning silently in the lobby of an Art Deco masterwork is a massive vintage model of the Earth.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

American revolutionaries and British soldiers alike are buried here in the fourth-ever cemetery in Boston.

The world's largest piece of copyrighted artwork.

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

This monument on Breed's Hill proves that one of the most famous battles of the Revolutionary War is misnamed.

This popular Boston haunt is reminiscent of a time gone by, when slow cafes and sweet-smelling smoke wafting from patios was the norm.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

Ice cream stand, snack bar, and time capsule of milk conveyance.

This massive tea kettle was once a promotional stunt for the Oriental Teashop.

This landmark cemetery in Boston was created more than 300 years ago.

This "life-size" depiction of Mickey Mouse as a half-lobster is both whimsical and a bit creepy, standing guard over the Boston waterfront.