This is a great shot.
I especially like this historic picture in the second link:
I believe it was taken about 1933
此图为喜峰口之鸟瞰图,中部为入口,内建围城二道,群山环抱,长城起伏于丛岭间,形势雄壮。
BING translation:
This photo shows a bird's eye view of the xifengkou, the Central as the entry the besieged city of erdaoling, the amplectant mountains, rugged mountains, the great wall, the witches'broom zhongling situation.
Historical picture of Xifengkou City.
"1933年初,日本侵略军占领东三省后,又出动海陆空军一起炮轰山海关,我守军苦战3日,终因寡不敌众, 山海关陷落。但却从这里响起了长城抗战第一枪。 这是29军在喜峰口抗击日军。"
I am not sure how accurate this translation is:
"In early 1933, after the Japanese occupation, and the three Northeast provinces were out in force with sea, land and army near Shanhai pass, I found fault with the British soldiers fight to the bitter 3rd outnumbered, Shanhai pass. But it was from here the first shot of the war of the great wall. This is 29 forces to fight the Japanese xifengkou."
This is an iconic photo as to why the Great Wall had become obsolete.
Or maybe the wall had been over-run by the Japanese.