《明史·列传·卷一百一十》
辽镇的边界长达二千多里，一百二十所城寨，三面毗邻敌人。
辽镇边长二千余里，城砦一百二十所，三面邻敌。
The boundary of Liaodong Militarised District was more than two thousand li in length, with one hundred and twenty castle-fortresses, and three sides bordering on the enemy.