朝宗橋又名沙河北大橋。位于昌平縣城南10公里、沙河鎮北0.5公里,鞏華城旁,跨北沙河水(溫榆河),與橫跨南沙河水上的“安濟橋”相對,相距2.5公里。 明朝遷都北京,在天壽山建陵墓,先后于明正統十二年(1447)拆掉南北沙河水上的木橋建石橋,北曰“朝宗”,南曰“安濟”。朝宗橋為七孔石橋。全長130米,寬13.3米,中間高7.5米,七孔聯拱結構,橋兩旁有石欄柱53對。是明朝帝后、大臣謁陵北巡的必經之路,又是通往塞北的交通咽喉。它與盧溝橋、永通橋(俗稱八里橋),并稱為“拱衛京師三大橋梁”。
大橋北端東側有明(ming)(ming)萬歷四年(nian)(1576)立的(de)螭首方座(zuo)漢白玉石碑(bei)一(yi)座(zuo),通(tong)高4.08米,寬1.1米,厚(hou)0.39米,立有明(ming)(ming)萬歷四年(nian)石碑(bei)1通(tong),碑(bei)額正背俱篆書“大明(ming)(ming)”二字(zi),碑(bei)身鐫刻大字(zi)“朝(chao)(chao)宗橋”。朝(chao)(chao)宗橋,地扼京(jing)師(shi)通(tong)往塞外要道咽喉,亦為明(ming)(ming)代帝后(hou)前(qian)往天壽寺(si)山(shan)謁陵(ling)朝(chao)(chao)宗祭(ji)祖的(de)必由之路。。為北京(jing)市重點保護文物。
朝(chao)(chao)宗(zong)橋(qiao)(qiao)(qiao)(qiao)(qiao)地理位置十分重要,橋(qiao)(qiao)(qiao)(qiao)(qiao)下(xia)的(de)(de)北(bei)(bei)沙(sha)(sha)(sha)(sha)河發源于北(bei)(bei)京(jing)昌平關溝山上(shang)(shang),沙(sha)(sha)(sha)(sha)河的(de)(de)下(xia)游(you)叫溫榆河,流入(ru)海河進(jin)入(ru)渤海。北(bei)(bei)沙(sha)(sha)(sha)(sha)河又有東(dong)沙(sha)(sha)(sha)(sha)河、南沙(sha)(sha)(sha)(sha)河兩個(ge)支流。早年(nian)(nian)(nian)(nian)每逢暴(bao)雨季節,洪水(shui)(shui)經常泛濫,遼金(jin)時期沙(sha)(sha)(sha)(sha)河上(shang)(shang)的(de)(de)木橋(qiao)(qiao)(qiao)(qiao)(qiao)經不(bu)起(qi)(qi)洪水(shui)(shui)的(de)(de)沖擊,時被(bei)沖垮,阻斷往(wang)來(lai),影響交通,在(zai)南沙(sha)(sha)(sha)(sha)河與北(bei)(bei)沙(sha)(sha)(sha)(sha)河交匯(hui)處(chu)的(de)(de)小鎮為(wei)沙(sha)(sha)(sha)(sha)河鎮,明代(dai)稱(cheng)沙(sha)(sha)(sha)(sha)河店,清代(dai)后改成沙(sha)(sha)(sha)(sha)河鎮。明正統年(nian)(nian)(nian)(nian)間撥專款建石(shi)拱(gong)橋(qiao)(qiao)(qiao)(qiao)(qiao),據《日下(xia)舊(jiu)聞考》記載:“安(an)濟(ji)、朝(chao)(chao)宗(zong),二橋(qiao)(qiao)(qiao)(qiao)(qiao)皆正統十二年(nian)(nian)(nian)(nian)(1447)命工部右(you)侍(shi)郎王永壽建。”是說在(zai)南北(bei)(bei)沙(sha)(sha)(sha)(sha)河上(shang)(shang)營建石(shi)橋(qiao)(qiao)(qiao)(qiao)(qiao)二座,南沙(sha)(sha)(sha)(sha)洞上(shang)(shang)稱(cheng)安(an)濟(ji)橋(qiao)(qiao)(qiao)(qiao)(qiao),北(bei)(bei)沙(sha)(sha)(sha)(sha)河上(shang)(shang)稱(cheng)朝(chao)(chao)宗(zong)橋(qiao)(qiao)(qiao)(qiao)(qiao),兩橋(qiao)(qiao)(qiao)(qiao)(qiao)可(ke)曰姐妹橋(qiao)(qiao)(qiao)(qiao)(qiao),當時是“拱(gong)衛(wei)京(jing)師五大(da)橋(qiao)(qiao)(qiao)(qiao)(qiao)”之(zhi)一。1937年(nian)(nian)(nian)(nian)7月侵華日軍炮轟朝(chao)(chao)宗(zong)橋(qiao)(qiao)(qiao)(qiao)(qiao),至今(jin)還留有痕(hen)跡(ji)。后來(lai)安(an)濟(ji)橋(qiao)(qiao)(qiao)(qiao)(qiao)因年(nian)(nian)(nian)(nian)久結構損壞(huai),建高速(su)(su)公(gong)路(lu)時被(bei)拆除,原址建起(qi)(qi)鋼筋(jin)水(shui)(shui)泥大(da)橋(qiao)(qiao)(qiao)(qiao)(qiao)。而朝(chao)(chao)宗(zong)橋(qiao)(qiao)(qiao)(qiao)(qiao)經歷(li)了數百年(nian)(nian)(nian)(nian)的(de)(de)風雨侵蝕、洪水(shui)(shui)沖擊,依舊(jiu)堅固(gu)如初。高速(su)(su)公(gong)路(lu)建在(zai)朝(chao)(chao)宗(zong)橋(qiao)(qiao)(qiao)(qiao)(qiao)的(de)(de)東(dong)側(ce),西側(ce)的(de)(de)輔路(lu)還在(zai)使用朝(chao)(chao)宗(zong)橋(qiao)(qiao)(qiao)(qiao)(qiao)。從明朝(chao)(chao)、清朝(chao)(chao)、民國時期到今(jin)天(tian),朝(chao)(chao)宗(zong)橋(qiao)(qiao)(qiao)(qiao)(qiao)被(bei)多(duo)次維護(hu)修理過(guo)。