The Yongning Gate (永寧門, meaning eternal peace), commonly known as the South Gate, is the grandest entrance to Xi'an's ancient City Wall. Built in AD 1370 during the Ming dynasty, it formed the main ceremonial gateway into the imperial city and was the principal entrance for visiting officials and dignitaries. The gate complex features a massive barbican, arrow tower, gate tower, drawbridge, and moat, illustrating the sophisticated military engineering of ancient China.