Tucson's Warehouse Arts District, managed by WAMO (the Warehouse Arts Management Organization), started in 2004 to preserve and promote buildings around downtown and the railroad tracks (where warehouses provided storage and transfer). You can read more about its history and significance in the National Endowment for the Arts page Tucson, AZ: Warehouse Arts District.
You could call the corner of 6th Street & 6th Avenue the center of Tucson's contemporary and alternative arts — galleries and studios. On that corner is The Royal Room. Here's the north side and a small mural with the Warehouse Arts District logo: