Masmak Fortress is a fortification finished in 1865, in the old town of Riyadh. On the stone blocks located at the base of the fortress are erected 1.25 meters thick walls of unfired brick, with towers at all corners, and within the walls are a mosque, a well, a majlis, and a courtyard. This fortification had a special role in the unification of Saudi Arabia, where the battle for Riyadh took place in this fortification. Today, it houses a museum that displays all important aspects of the country's history.