Ksar Draa stands as a mysterious fortified citadel in the remote Timimoun region of Algeria's Sahara Desert, distinguished by its enigmatic history and remarkable architectural preservation. The structure consists of two concentric circular outer walls constructed from sand, straw, and clay, standing approximately 10 meters tall with walls reaching up to 2 meters thick, featuring a single entrance and no exterior windows. Inside, three levels contain living spaces, communal kitchens, and a mosque serving the structure's inhabitants. The exact date of construction, builders, and reason for abandonment remain unknown, with historians theorizing it may have functioned as a caravanserai, fortified castle, prison, granary, or trading post. Some sources suggest Jewish residents of the Timimoun region occupied it historically. Reaching this isolated desert monument requires expert guides and four-wheel-drive vehicles or camels to navigate the surrounding sand dunes.