燕山

East-west range along northern Hebei and the top of Beijing Municipality. Carries long stretches of the Great Wall (八达岭 Badaling, 金山岭 Jinshanling, 司马台 Simatai all lie on it) and historically defined the frontier between Han-Chinese agriculture and the northern steppe. Name comes from the ancient state of Yan (燕). Read first-tone Yān - do not confuse with 燕子 yànzi (swallow).

燕 has two readings: Yān (first tone, the Yan state, the Yan Mountains, Beijing's old name 燕京) and yàn (fourth tone, swallow). Mountain or place name = Yān.