Gun emplacement (Tatooine)
Gun emplacements were placed on Tatooine by the desert stormtrooper unit Desert Sands under the orders of Darth Vader around the time of the Battle of Tatooine, largely to deal with Rebels in the area.
Luke Skywalker, when trying to find R2-D2 and later Mos Eisley, had to evade their constant barrages in his landspeeder.