I imagine a group of bandits holed up in the tower and rob travelers. But they really only take supplies so they can keep using the tower as a base of operations to look for a treasure they have a map to that is hidden in the sands... It probably isn't going well ;P. I included more information on the PDF for this map on my Ko-Fi. You can get it for free here: https://ko-fi.com/s/ee750a849a