大(da)(da)同(tong)(tong)(tong)古長(chang)(chang)城(cheng)(cheng)是萬里長(chang)(chang)城(cheng)(cheng)的(de)(de)(de)(de)(de)(de)重要組成(cheng)部(bu)(bu)分,主要分布于大(da)(da)同(tong)(tong)(tong)市(shi)的(de)(de)(de)(de)(de)(de)天(tian)鎮縣、陽(yang)高縣、新(xin)榮(rong)區(qu)(qu)、左(zuo)云縣、渾源(yuan)縣、靈(ling)丘(qiu)縣、廣靈(ling)縣7個縣區(qu)(qu)。大(da)(da)同(tong)(tong)(tong)的(de)(de)(de)(de)(de)(de)長(chang)(chang)城(cheng)(cheng)歷史所跨(kua)朝代(dai)(dai)較多,現存主要是明(ming)(ming)(ming)代(dai)(dai)長(chang)(chang)城(cheng)(cheng)。大(da)(da)同(tong)(tong)(tong)作(zuo)為(wei)當時拱衛(wei)京都的(de)(de)(de)(de)(de)(de)屏障,明(ming)(ming)(ming)長(chang)(chang)城(cheng)(cheng)分外(wai)長(chang)(chang)城(cheng)(cheng)和內(nei)(nei)(nei)長(chang)(chang)城(cheng)(cheng),如今(jin)的(de)(de)(de)(de)(de)(de)大(da)(da)同(tong)(tong)(tong)市(shi)居于內(nei)(nei)(nei)外(wai)長(chang)(chang)城(cheng)(cheng)之間,南(nan)部(bu)(bu)和北(bei)部(bu)(bu)、西(xi)部(bu)(bu)的(de)(de)(de)(de)(de)(de)行政區(qu)(qu)劃(hua)線大(da)(da)部(bu)(bu)分以長(chang)(chang)城(cheng)(cheng)為(wei)界。2009年公布的(de)(de)(de)(de)(de)(de)長(chang)(chang)城(cheng)(cheng)資源(yuan)調查數據中,大(da)(da)同(tong)(tong)(tong)市(shi)境(jing)內(nei)(nei)(nei)明(ming)(ming)(ming)代(dai)(dai)長(chang)(chang)城(cheng)(cheng)343167米,共有長(chang)(chang)城(cheng)(cheng)烽(feng)火臺、古堡等(deng)843處(chu)(chu)。1986年8月18日(ri),大(da)(da)同(tong)(tong)(tong)長(chang)(chang)城(cheng)(cheng)被(bei)山西(xi)省人(ren)民政府公布為(wei)第二批省級(ji)文(wen)物(wu)保護單位。相(xiang)關的(de)(de)(de)(de)(de)(de)壁畫、雕刻、碑文(wen)等(deng)與(yu)長(chang)(chang)城(cheng)(cheng)有直接關系的(de)(de)(de)(de)(de)(de)文(wen)物(wu)超過2000處(chu)(chu)。天(tian)鎮縣新(xin)平堡的(de)(de)(de)(de)(de)(de)玉(yu)皇(huang)閣鎮邊樓以及修在海拔1736米山頂(ding)上的(de)(de)(de)(de)(de)(de)樺門堡,陽(yang)高縣墩臺密布的(de)(de)(de)(de)(de)(de)長(chang)(chang)城(cheng)(cheng)鄉,新(xin)榮(rong)區(qu)(qu)拱衛(wei)北(bei)魏(wei)皇(huang)陵的(de)(de)(de)(de)(de)(de)方山長(chang)(chang)城(cheng)(cheng)和得勝堡等(deng)邊墻(qiang)五堡,左(zuo)云摩天(tian)嶺兩個制高點之間的(de)(de)(de)(de)(de)(de)寧魯樓,靈(ling)丘(qiu)牛幫口的(de)(de)(de)(de)(de)(de)內(nei)(nei)(nei)長(chang)(chang)城(cheng)(cheng)都是大(da)(da)同(tong)(tong)(tong)長(chang)(chang)城(cheng)(cheng)的(de)(de)(de)(de)(de)(de)精(jing)美(mei)華章。
據《三(san)云(yun)(yun)籌俎考·大(da)(da)(da)同(tong)(tong)總鎮(zhen)(zhen)(zhen)圖說》統(tong)計(ji),大(da)(da)(da)同(tong)(tong)鎮(zhen)(zhen)(zhen)先后(hou)修大(da)(da)(da)邊(bian)(bian)(bian)、二(er)邊(bian)(bian)(bian)516.3里(li)(li);內(nei)五堡(bao)(bao)(bao)、外五堡(bao)(bao)(bao)、塞外五堡(bao)(bao)(bao)、云(yun)(yun)岡六堡(bao)(bao)(bao)等主(zhu)要城(cheng)(cheng)(cheng)(cheng)堡(bao)(bao)(bao)72座(zuo)(城(cheng)(cheng)(cheng)(cheng)20,堡(bao)(bao)(bao)52);邊(bian)(bian)(bian)城(cheng)(cheng)(cheng)(cheng)776個;火路(lu)墩(dun)833個。在大(da)(da)(da)同(tong)(tong)明長(chang)城(cheng)(cheng)(cheng)(cheng)自居庸關(guan)以西(xi)(xi)(xi),分南(nan)北(bei)兩線到山西(xi)(xi)(xi)偏關(guan)會合,被稱為內(nei)、外長(chang)城(cheng)(cheng)(cheng)(cheng)。外長(chang)城(cheng)(cheng)(cheng)(cheng)即居庸關(guan)西(xi)(xi)(xi)北(bei)經赤城(cheng)(cheng)(cheng)(cheng)、崇(chong)禮、張家口(kou)、萬(wan)全、懷(huai)(huai)安而(er)進(jin)(jin)入(ru)(ru)(ru)(ru)大(da)(da)(da)同(tong)(tong)市(shi)(shi)的(de)(de)天(tian)(tian)鎮(zhen)(zhen)(zhen)、陽(yang)高、大(da)(da)(da)同(tong)(tong)、左云(yun)(yun)沿內(nei)蒙古(gu)、山西(xi)(xi)(xi)交界(jie)(jie)處(chu),達于偏關(guan)、河(he)曲;內(nei)長(chang)城(cheng)(cheng)(cheng)(cheng)從(cong)居庸關(guan)西(xi)(xi)(xi)南(nan)經河(he)北(bei)易縣、渾(hun)源(yuan)(yuan)、阜平而(er)進(jin)(jin)入(ru)(ru)(ru)(ru)大(da)(da)(da)同(tong)(tong)市(shi)(shi)的(de)(de)靈(ling)丘、渾(hun)源(yuan)(yuan),再(zai)經應縣、繁(fan)峙、神池而(er)至(zhi)老(lao)營。據現存(cun)長(chang)城(cheng)(cheng)(cheng)(cheng)實測,外長(chang)城(cheng)(cheng)(cheng)(cheng)分別由(you)懷(huai)(huai)安縣桃溝(gou)村、西(xi)(xi)(xi)洋(yang)河(he)鄉馬市(shi)(shi)口(kou)南(nan)北(bei)兩路(lu)進(jin)(jin)入(ru)(ru)(ru)(ru)天(tian)(tian)鎮(zhen)(zhen)(zhen)縣境(jing)(jing)(jing),在新(xin)平樂(le)村與西(xi)(xi)(xi)路(lu)長(chang)城(cheng)(cheng)(cheng)(cheng)相(xiang)交。天(tian)(tian)鎮(zhen)(zhen)(zhen)境(jing)(jing)(jing)內(nei)長(chang)城(cheng)(cheng)(cheng)(cheng)約(yue) 105華(hua)里(li)(li),存(cun)黃土(tu)夯(hang)筑的(de)(de)墩(dun)臺(tai)61座(zuo)。由(you)天(tian)(tian)鎮(zhen)(zhen)(zhen)水(shui)磨口(kou)向(xiang)(xiang)西(xi)(xi)(xi)三(san)里(li)(li)進(jin)(jin)入(ru)(ru)(ru)(ru)陽(yang)高縣十(shi)九墩(dun)村界(jie)(jie),至(zhi)鎮(zhen)(zhen)(zhen)邊(bian)(bian)(bian)堡(bao)(bao)(bao)西(xi)(xi)(xi)出陽(yang)高進(jin)(jin)入(ru)(ru)(ru)(ru)大(da)(da)(da)同(tong)(tong)市(shi)(shi)區(qu)境(jing)(jing)(jing)。陽(yang)高境(jing)(jing)(jing)內(nei)長(chang)城(cheng)(cheng)(cheng)(cheng)計(ji) 100余里(li)(li),現存(cun)夯(hang)土(tu)處(chu)臺(tai) 119座(zuo)。從(cong)陽(yang)高鎮(zhen)(zhen)(zhen)邊(bian)(bian)(bian)堡(bao)(bao)(bao)向(xiang)(xiang)西(xi)(xi)(xi)約(yue)八華(hua)里(li)(li)進(jin)(jin)入(ru)(ru)(ru)(ru)大(da)(da)(da)同(tong)(tong)元墩(dun)村界(jie)(jie),經鎮(zhen)(zhen)(zhen)川口(kou)、宏賜堡(bao)(bao)(bao)、鎮(zhen)(zhen)(zhen)羌堡(bao)(bao)(bao),經拒墻口(kou)、拒門口(kou)、助馬口(kou)至(zhi)十(shi)三(san)邊(bian)(bian)(bian),轉南(nan)至(zhi)磚樓溝(gou)入(ru)(ru)(ru)(ru)左云(yun)(yun)縣界(jie)(jie)。另一(yi)條(tiao)由(you)宏賜堡(bao)(bao)(bao)向(xiang)(xiang)西(xi)(xi)(xi)經新(xin)榮、破(po)魯至(zhi)吳(wu)施(shi)窯入(ru)(ru)(ru)(ru)左云(yun)(yun)界(jie)(jie),這道長(chang)城(cheng)(cheng)(cheng)(cheng)當地人稱“二(er)道邊(bian)(bian)(bian)”。南(nan)北(bei)兩道長(chang)城(cheng)(cheng)(cheng)(cheng)共 210華(hua)里(li)(li)。長(chang)城(cheng)(cheng)(cheng)(cheng)由(you)大(da)(da)(da)同(tong)(tong)磚樓向(xiang)(xiang)南(nan)進(jin)(jin)入(ru)(ru)(ru)(ru)左云(yun)(yun)縣保(bao)安堡(bao)(bao)(bao)地界(jie)(jie),至(zhi)二(er)十(shi)邊(bian)(bian)(bian)向(xiang)(xiang)西(xi)(xi)(xi)北(bei)出左云(yun)(yun)進(jin)(jin)入(ru)(ru)(ru)(ru)右玉縣界(jie)(jie)。長(chang)城(cheng)(cheng)(cheng)(cheng)在左云(yun)(yun)境(jing)(jing)(jing)內(nei)長(chang)約(yue)86華(hua)里(li)(li)。以上這段長(chang)城(cheng)(cheng)(cheng)(cheng)在大(da)(da)(da)同(tong)(tong)市(shi)(shi)境(jing)(jing)(jing)內(nei)約(yue)長(chang) 501華(hua)里(li)(li)。大(da)(da)(da)同(tong)(tong)市(shi)(shi)、渾(hun)源(yuan)(yuan)、靈(ling)丘縣境(jing)(jing)(jing)內(nei)的(de)(de)明長(chang)城(cheng)(cheng)(cheng)(cheng)周(zhou)內(nei)長(chang)城(cheng)(cheng)(cheng)(cheng)。渾(hun)源(yuan)(yuan)境(jing)(jing)(jing)內(nei)計(ji) 160華(hua)里(li)(li),靈(ling)丘境(jing)(jing)(jing)內(nei)長(chang)約(yue) 190華(hua)里(li)(li)。明內(nei)、外長(chang)城(cheng)(cheng)(cheng)(cheng)在大(da)(da)(da)同(tong)(tong)境(jing)(jing)(jing)內(nei)總長(chang)為 800多(duo)華(hua)里(li)(li)。為山西(xi)(xi)(xi)省重點文物保(bao)護單位。