Slab City, / The Last Free Place In The America / Squat Town USA. Photo documenting Slab City , I came upon this Joshua Tree where visiters or residents can take a pair or leave a pair of shoes. Slab City occupies 640 Acres and is located in California’s Sonoran Desert. The name refers to the concrete slabs that were once facilities used during WW 11 as a military training site. Ft. Dunlop was abandoned in the 1950’s. People now come here to live alturnative life styles on this unincorporated land, off the grid, rent - free and lawless.