An ancient glacial pothole waterfall in the heart of the Green Mountains.

A beautiful, creepy 19th-century castle stands incongruous in rural Vermont.

The world’s largest underground marble quarry is hiding in Vermont.

This cavernous abandoned marble mine is popular with ice skaters in the winter.

The place where the great marine explorer first learned to work underwater is not where you'd expect.

A former zoo turned public park, where visitors can hang out in the old animal cages.

Where Kevin Eastman and Peter Laird created their "heroes in a half shell" and founded Mirage Studios.

The only one of New Hampshire's original 14 World War II watchtowers to survive in near-original condition.

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

One of the now-less-hidden floral gems of the "Emerald Necklace."

One of the last remaining World War II Victory Gardens in the U.S. is quietly growing across from Fenway Park.

This Dutch-styled residential building was originally a cocoa company's World's Fair showpiece.

Beautiful steampunk ghosts of early Massachusetts.

Deep under Manhattan is the largest construction project in city history. So far, the project has taken the lives of 23 workers, or "a man a mile."