The Senora Desert Structure is located southwest of the Sandy Shores airfield and due east from Harmony.
The structure is built into a hill in the desert, using similar textures to the Abandoned Mine Shaft, but there are extra wooden support beams on the outside. There is no trail or any signs that the structure was used recently, and no indication of what exactly the building was used for. It is presumed to be a mine shaft entrance, but due to its proximity to the airstrip, it could be an abandoned bomb shelter. There is currently no way to enter it, as the large wooden door is immune to explosives and gunfire.
The area inside is a single hollowed out room that is only a few square feet, filled with nothing but a pile of rocks on one side.
It is currently inaccessible and serves no actual purpose in GTA V's storyline.
Although they are not well known and are overlooked, fan rumors on the internet state that loud metallic noises, similar to the "skyquake" phenomena, can be heard while the player is near the entrance of the structure. These claims have never been decisively proven.