The largest self-built castle in the U.S., six decades in the making.

This chilly Canadian hotel has a four-month lifespan due to the unusual material it's made of.

An 80-year-old house built out of newspapers.

Beach instrument turned bed and breakfast.

A former poultry store that looks like a giant duck and is one of the "seven wonders" of Long Island.

The world's largest kaleidoscope, designed by a 1960s psychedelic artist.

A Cuban artist reclaimed his impoverished neighborhood as a dreamy folk art kingdom.

Eclectic architecture in the woods of New York.

A bedazzled house and crown "jewel" of outsider artist Loy Allen Bowlin.

Concrete igloos standing across from what remains of the Michigan Central train depot.

Tour the luxe "glass cage" that inspired and unnerved the architecture world upon its debut.

A peaceful place in the woods where everything is a work in progress.

Site of a former hidden treehouse in New Orleans.

A cabin completely covered in coffee mugs, where visitors are welcome to leave one of their own—if they can find an empty nail.

This structure among the trees was the result of divine inspiration.

Live long and prosper in Tennessee.