Seaside is an unincorporated master-planned community on the Florida Panhandle in Walton County, between Panama City Beach and Destin. One of the first communities in America designed on the principles of New Urbanism, the town has become the topic of slide lectures in architectural schools and in housing-industry magazines, and is visited by design …Seaside is an unincorporated master-planned community on the Florida Panhandle in Walton County, between Panama City Beach and Destin. One of the first communities in America designed on the principles of New Urbanism, the town has become the topic of slide lectures in architectural schools and in housing-industry magazines, and is visited by design professionals from all over the United States.