A hidden workshop for creating and restoring Papal mosaic masterpieces.

The inspiration for H.P. Lovecraft's horror stories and Batman's Arkham Asylum is now a condominium complex.

The self-proclaimed world's smallest museum, located next to a Massachusetts sandwich chain.

This tiny, painted door at the base of a tree stump has been a fixture of the Harvard University campus for decades.

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

An easy-to-miss garden in Boston's North End honors the mother of JFK and others who lost children in WWII.

No one messes with the Massachusetts sacred cod, not this time...

Painstakingly built dioramas sit unnoticed in a Boston office building.

The tomb of Increase Mather and his son Cotton, influential colonial ministers obsessed with the occult.

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

Beautiful steampunk ghosts of early Massachusetts.

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

Radical Bookstore and Community Space.

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

The old fire tower is one of the last of its kind in the United States.

A late-medieval Dutch castle with trick fountains in its whimsical water gardens.

This incredible college library is a visual masterpiece of mosaic art. It also looks kind of like a giant boombox.

A monument to the 17,000 Chinese who worked and died to build Canada's Pacific Railway.

An arresting temple full of mosaics as colorful as the politician they memorialize.

A New England curiosity cabinet, one hundred years on.

A small chapel celebrating the spiritual bond between dogs and humans.

A massive sustainable farm designed by the mastermind behind Central Park.

Scary metal statues adorn some of the signature buildings of Burlington, Vermont.

Cryptid lake monster honored with its own monument.