The rustic cabin-like decor of this Arts and Crafts-style church reflects the love of nature central to its little-known theology.

A grotesque Fiji merman dwells within this traditional Dutch-style building.

A museum dedicated to exhibiting remarkable outsider art.

The narrowest house in America is seven feet of pure spite.

This historic mansion was built as a symbol of love between a husband and wife.

Heron, whitewater rapids, and urban industrialism all add to the beauty of this concrete nature walk.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

A secretive collection featuring objects that were designed specifically for U.S. intelligence operations.

A 300-yard long natural tunnel runs through a ridge deep in the Appalachian Mountains.

Giant busts of 42 U.S. presidents are sitting in a field in Virginia.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

The remains of a failed attempt at medieval nerdery are hidden deep in the woods of Virginia.

A scenic fort on the harbor protected Philadelphia from an attack that never came.

This splendid Versailles-inspired mansion has the largest French-style formal gardens in North America.

Enchanting gardens surround a derelict mansion, all hidden in plain sight behind a stone wall.

A blend of art, antiquities, and Americana fill this museum, surrounded by whimsical, enchanting gardens.

A safari-themed castle in the South African bush with the largest maze in the southern hemisphere.

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

Eighteen miniature death-scene dioramas.

The land is home to swimming ponies and a legendary 18th-century treasure.