Welcome to 1401 Mississippi Ave — known around Duluth for more than fifty years as "The Mushroom House" or "The Flinstone House." The 5-bedroom, 3-bath house was built in 1970 using an innovative foam-shell construction method. The home's triple-dome design creates curved walls, soaring dome ceilings, and spaces that feel more sculpted than built. The primary bedroom offers vaulted ceilings and epoxy flooring. Three additional bedrooms, a full bath, a half bath, and a laundry room create flexibility for whatever the next owner needs.