大(da)同古長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)是(shi)萬里長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)的(de)(de)(de)(de)(de)(de)重要組(zu)成部(bu)(bu)(bu)分(fen)(fen),主(zhu)要分(fen)(fen)布(bu)(bu)于大(da)同市的(de)(de)(de)(de)(de)(de)天(tian)鎮縣(xian)(xian)、陽(yang)高縣(xian)(xian)、新榮區(qu)、左(zuo)(zuo)云(yun)縣(xian)(xian)、渾源(yuan)縣(xian)(xian)、靈丘(qiu)縣(xian)(xian)、廣靈縣(xian)(xian)7個縣(xian)(xian)區(qu)。大(da)同的(de)(de)(de)(de)(de)(de)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)歷史(shi)所跨朝代較多,現存主(zhu)要是(shi)明(ming)(ming)(ming)代長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)。大(da)同作為當時(shi)拱(gong)(gong)衛京都的(de)(de)(de)(de)(de)(de)屏障,明(ming)(ming)(ming)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)分(fen)(fen)外長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)和內(nei)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng),如今的(de)(de)(de)(de)(de)(de)大(da)同市居于內(nei)外長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)之間(jian),南(nan)部(bu)(bu)(bu)和北部(bu)(bu)(bu)、西部(bu)(bu)(bu)的(de)(de)(de)(de)(de)(de)行政區(qu)劃線(xian)大(da)部(bu)(bu)(bu)分(fen)(fen)以(yi)(yi)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)為界。2009年公布(bu)(bu)的(de)(de)(de)(de)(de)(de)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)資源(yuan)調(diao)查數據(ju)中,大(da)同市境內(nei)明(ming)(ming)(ming)代長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)343167米,共有(you)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)烽火臺(tai)、古堡(bao)等(deng)843處。1986年8月18日,大(da)同長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)被山(shan)西省人民(min)政府公布(bu)(bu)為第(di)二批省級(ji)文(wen)物(wu)保護單位。相關的(de)(de)(de)(de)(de)(de)壁畫、雕(diao)刻、碑(bei)文(wen)等(deng)與長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)有(you)直接關系(xi)的(de)(de)(de)(de)(de)(de)文(wen)物(wu)超過2000處。天(tian)鎮縣(xian)(xian)新平堡(bao)的(de)(de)(de)(de)(de)(de)玉皇(huang)閣鎮邊樓以(yi)(yi)及(ji)修在海拔1736米山(shan)頂上的(de)(de)(de)(de)(de)(de)樺門堡(bao),陽(yang)高縣(xian)(xian)墩臺(tai)密布(bu)(bu)的(de)(de)(de)(de)(de)(de)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)鄉,新榮區(qu)拱(gong)(gong)衛北魏皇(huang)陵的(de)(de)(de)(de)(de)(de)方山(shan)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)和得勝堡(bao)等(deng)邊墻五堡(bao),左(zuo)(zuo)云(yun)摩(mo)天(tian)嶺(ling)兩個制(zhi)高點之間(jian)的(de)(de)(de)(de)(de)(de)寧魯樓,靈丘(qiu)牛幫口的(de)(de)(de)(de)(de)(de)內(nei)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)都是(shi)大(da)同長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)的(de)(de)(de)(de)(de)(de)精美華(hua)章(zhang)。
據《三(san)云(yun)(yun)籌俎考·大(da)(da)(da)(da)同(tong)總鎮(zhen)圖說(shuo)》統計,大(da)(da)(da)(da)同(tong)鎮(zhen)先后修(xiu)大(da)(da)(da)(da)邊(bian)、二邊(bian)516.3里(li);內(nei)(nei)(nei)(nei)(nei)(nei)五堡(bao)、外(wai)(wai)五堡(bao)、塞外(wai)(wai)五堡(bao)、云(yun)(yun)岡六堡(bao)等主要城(cheng)(cheng)(cheng)(cheng)堡(bao)72座(zuo)(zuo)(城(cheng)(cheng)(cheng)(cheng)20,堡(bao)52);邊(bian)城(cheng)(cheng)(cheng)(cheng)776個;火路墩833個。在(zai)大(da)(da)(da)(da)同(tong)明(ming)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)自居庸(yong)(yong)關以西(xi)(xi)(xi)(xi)(xi),分南(nan)北(bei)兩(liang)線到山(shan)西(xi)(xi)(xi)(xi)(xi)偏關會合(he),被稱為內(nei)(nei)(nei)(nei)(nei)(nei)、外(wai)(wai)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)。外(wai)(wai)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)即居庸(yong)(yong)關西(xi)(xi)(xi)(xi)(xi)北(bei)經(jing)赤城(cheng)(cheng)(cheng)(cheng)、崇禮、張家口(kou)(kou)、萬全、懷安(an)而(er)進入(ru)(ru)(ru)(ru)大(da)(da)(da)(da)同(tong)市(shi)(shi)的天鎮(zhen)、陽(yang)(yang)(yang)高、大(da)(da)(da)(da)同(tong)、左(zuo)云(yun)(yun)沿內(nei)(nei)(nei)(nei)(nei)(nei)蒙古、山(shan)西(xi)(xi)(xi)(xi)(xi)交(jiao)界(jie)(jie)(jie)(jie)處,達于偏關、河曲;內(nei)(nei)(nei)(nei)(nei)(nei)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)從居庸(yong)(yong)關西(xi)(xi)(xi)(xi)(xi)南(nan)經(jing)河北(bei)易(yi)縣(xian)(xian)(xian)、渾源(yuan)、阜平(ping)而(er)進入(ru)(ru)(ru)(ru)大(da)(da)(da)(da)同(tong)市(shi)(shi)的靈丘(qiu)、渾源(yuan),再(zai)經(jing)應(ying)縣(xian)(xian)(xian)、繁峙、神(shen)池而(er)至(zhi)(zhi)(zhi)(zhi)老營(ying)。據現(xian)存(cun)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)實測(ce),外(wai)(wai)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)分別由懷安(an)縣(xian)(xian)(xian)桃溝(gou)村、西(xi)(xi)(xi)(xi)(xi)洋河鄉馬(ma)市(shi)(shi)口(kou)(kou)南(nan)北(bei)兩(liang)路進入(ru)(ru)(ru)(ru)天鎮(zhen)縣(xian)(xian)(xian)境(jing),在(zai)新(xin)平(ping)樂村與西(xi)(xi)(xi)(xi)(xi)路長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)相交(jiao)。天鎮(zhen)境(jing)內(nei)(nei)(nei)(nei)(nei)(nei)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)約 105華(hua)(hua)(hua)里(li),存(cun)黃土(tu)夯(hang)筑的墩臺61座(zuo)(zuo)。由天鎮(zhen)水磨口(kou)(kou)向(xiang)西(xi)(xi)(xi)(xi)(xi)三(san)里(li)進入(ru)(ru)(ru)(ru)陽(yang)(yang)(yang)高縣(xian)(xian)(xian)十(shi)九墩村界(jie)(jie)(jie)(jie),至(zhi)(zhi)(zhi)(zhi)鎮(zhen)邊(bian)堡(bao)西(xi)(xi)(xi)(xi)(xi)出(chu)陽(yang)(yang)(yang)高進入(ru)(ru)(ru)(ru)大(da)(da)(da)(da)同(tong)市(shi)(shi)區境(jing)。陽(yang)(yang)(yang)高境(jing)內(nei)(nei)(nei)(nei)(nei)(nei)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)計 100余里(li),現(xian)存(cun)夯(hang)土(tu)處臺 119座(zuo)(zuo)。從陽(yang)(yang)(yang)高鎮(zhen)邊(bian)堡(bao)向(xiang)西(xi)(xi)(xi)(xi)(xi)約八華(hua)(hua)(hua)里(li)進入(ru)(ru)(ru)(ru)大(da)(da)(da)(da)同(tong)元墩村界(jie)(jie)(jie)(jie),經(jing)鎮(zhen)川口(kou)(kou)、宏賜(si)堡(bao)、鎮(zhen)羌堡(bao),經(jing)拒(ju)墻(qiang)口(kou)(kou)、拒(ju)門口(kou)(kou)、助馬(ma)口(kou)(kou)至(zhi)(zhi)(zhi)(zhi)十(shi)三(san)邊(bian),轉南(nan)至(zhi)(zhi)(zhi)(zhi)磚樓溝(gou)入(ru)(ru)(ru)(ru)左(zuo)云(yun)(yun)縣(xian)(xian)(xian)界(jie)(jie)(jie)(jie)。另一條由宏賜(si)堡(bao)向(xiang)西(xi)(xi)(xi)(xi)(xi)經(jing)新(xin)榮(rong)、破魯至(zhi)(zhi)(zhi)(zhi)吳施窯入(ru)(ru)(ru)(ru)左(zuo)云(yun)(yun)界(jie)(jie)(jie)(jie),這(zhe)道(dao)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)當地人稱“二道(dao)邊(bian)”。南(nan)北(bei)兩(liang)道(dao)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)共 210華(hua)(hua)(hua)里(li)。長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)由大(da)(da)(da)(da)同(tong)磚樓向(xiang)南(nan)進入(ru)(ru)(ru)(ru)左(zuo)云(yun)(yun)縣(xian)(xian)(xian)保(bao)安(an)堡(bao)地界(jie)(jie)(jie)(jie),至(zhi)(zhi)(zhi)(zhi)二十(shi)邊(bian)向(xiang)西(xi)(xi)(xi)(xi)(xi)北(bei)出(chu)左(zuo)云(yun)(yun)進入(ru)(ru)(ru)(ru)右玉(yu)縣(xian)(xian)(xian)界(jie)(jie)(jie)(jie)。長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)在(zai)左(zuo)云(yun)(yun)境(jing)內(nei)(nei)(nei)(nei)(nei)(nei)長(chang)(chang)(chang)(chang)約86華(hua)(hua)(hua)里(li)。以上這(zhe)段(duan)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)在(zai)大(da)(da)(da)(da)同(tong)市(shi)(shi)境(jing)內(nei)(nei)(nei)(nei)(nei)(nei)約長(chang)(chang)(chang)(chang) 501華(hua)(hua)(hua)里(li)。大(da)(da)(da)(da)同(tong)市(shi)(shi)、渾源(yuan)、靈丘(qiu)縣(xian)(xian)(xian)境(jing)內(nei)(nei)(nei)(nei)(nei)(nei)的明(ming)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)周內(nei)(nei)(nei)(nei)(nei)(nei)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)。渾源(yuan)境(jing)內(nei)(nei)(nei)(nei)(nei)(nei)計 160華(hua)(hua)(hua)里(li),靈丘(qiu)境(jing)內(nei)(nei)(nei)(nei)(nei)(nei)長(chang)(chang)(chang)(chang)約 190華(hua)(hua)(hua)里(li)。明(ming)內(nei)(nei)(nei)(nei)(nei)(nei)、外(wai)(wai)長(chang)(chang)(chang)(chang)城(cheng)(cheng)(cheng)(cheng)在(zai)大(da)(da)(da)(da)同(tong)境(jing)內(nei)(nei)(nei)(nei)(nei)(nei)總長(chang)(chang)(chang)(chang)為 800多(duo)華(hua)(hua)(hua)里(li)。為山(shan)西(xi)(xi)(xi)(xi)(xi)省重(zhong)點文物保(bao)護單位。