Painstakingly built dioramas sit unnoticed in a Boston office building.

The massive machine creates cracking displays of indoor lightning.

Beautiful steampunk ghosts of early Massachusetts.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

The Boston square dedicated to the dark poet who was born nearby.

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

The site of one of the strangest disasters in history—a wave of deadly molasses traveling at 35 mph.

This upscale streetwear store is hidden behind a fake Snapple machine in the back of a deli.

This Boston medical museum features the skull of the famous medical case of Phineas Gage.

Silverware in the sidewalk outside a grocery store cements this neighborhood’s Italian culinary history.

A popular 19th-century natural landmark is now hidden within a sprawling forest.

Around 100 sculptures from artists all over the world decorate the hiking trails surrounding this locale.

A beautiful multicolored mound formed by the mineral deposits of the Orenda Spring.

Tucked behind New Jersey's abandoned Gingerbread Castle lie the eerie ruins of a once-flourishing paper mill.

This old-fashioned candy shop, ice cream parlor, and diner served as the setting for one of TV's most controversial series finales.

Step into Monet's world at this fine-dining restaurant in the middle of a New Jersey sculpture park.

A unique sculpture park that specializes in the huge and bizarre.

Board a mine car and descend the #190 slope 300 feet underground into the Clark Vein of coal.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

Hidden in a grotto 26 feet below Nottingham's oldest hotel, this stylish subterranean drinking den is notoriously hard to find.

In a 345-million-year-old cave that's 200 feet underground, dinner awaits.

Sail through this subterranean show cave that is home to a legend that would go on to name nearly everything around it.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

Philadelphia boasts one of the best — and most often overlooked — traditional Japanese gardens in North America.