位于(yu)固原縣(xian)七(qi)營鄉以北5公(gong)(gong)(gong)里的(de)北嘴村。城(cheng)(cheng)東(dong)(dong)西寬(kuan)600米(mi)(mi),南北長(chang)650米(mi)(mi),有內城(cheng)(cheng),南北寬(kuan)450米(mi)(mi),東(dong)(dong)西長(chang)550米(mi)(mi)。城(cheng)(cheng)內東(dong)(dong)北角有100米(mi)(mi)見方的(de)小城(cheng)(cheng)堡,外(wai)有甕(weng)城(cheng)(cheng),長(chang)96米(mi)(mi),寬(kuan)36米(mi)(mi)。現存城(cheng)(cheng)墻高1—5米(mi)(mi),頂寬(kuan)1米(mi)(mi),基寬(kuan)9.5米(mi)(mi)。據載:此城(cheng)(cheng)建于(yu)隋(sui),大業初(chu),為(wei)他(ta)樓縣(xian)治(zhi)。唐(tang)神龍元(yuan)(yuan)年(公(gong)(gong)(gong)元(yuan)(yuan)701年)廢,改蕭(xiao)關縣(xian)。大中五年(公(gong)(gong)(gong)元(yuan)(yuan)852年)治(zhi)五州。經宋(song)、元(yuan)(yuan),廢于(yu)明萬(wan)歷年間,該城(cheng)(cheng)系固原保存較好的(de)一座(zuo)古城(cheng)(cheng)址。