The ancient Roman and mediaeval city walls of Damascus form a weathered limestone shield around the historic Old Town. Among the most iconic entry points is Bab Sharqi, or the "Gate of the Sun", which is the only Roman-era gate to retain its original triple-arch design. Nearby, the northern Bab Touma gate is somewhat marooned and neglected amidst traffic but forms the heart of the Christian Quarter and has the most atmospheric parts of the fortified wall to the east and west. Bab al-Saghir gate in the south leads towards the city's most significant cemetery.