長樂宮遺(yi)址即現在(zai)的未央區閣老門、唐寨(zhai)、張(zhang)家巷、羅寨(zhai)、講武殿(dian)、中查、西(xi)查、東查，樊寨(zhai)和雷寨(zhai)等村莊(zhuang)。
長(chang)(chang)(chang)樂(le)宮(gong)(gong)的考(kao)古工作開始于(yu)1956年。經(jing)勘(kan)查(cha)，該宮(gong)(gong)平面(mian)(mian)(mian)形(xing)狀不規整，周長(chang)(chang)(chang)約10千(qian)米(mi)，面(mian)(mian)(mian)積約6平方(fang)千(qian)米(mi)，占長(chang)(chang)(chang)安城總面(mian)(mian)(mian)積的六分之一左右。宮(gong)(gong)墻四門遺跡尚能辨認(ren)，宮(gong)(gong)內建筑已完全湮(yin)滅，只有長(chang)(chang)(chang)信宮(gong)(gong)、長(chang)(chang)(chang)秋宮(gong)(gong)等少(shao)數宮(gong)(gong)室(shi)，可據出土(tu)物印證。通過(guo)發(fa)掘表明(ming)，長(chang)(chang)(chang)樂(le)宮(gong)(gong)在(zai)東(dong)漢還保存完好(hao)，五代(dai)十(shi)國以后廢棄(qi)。
長樂宮遺址曾出(chu)土罕見排(pai)(pai)(pai)水(shui)渠(qu)(qu)(qu)道，在一(yi)米(mi)多深的(de)(de)地下，兩組陶質排(pai)(pai)(pai)水(shui)管(guan)道如(ru)兩條(tiao)南(nan)北(bei)向的(de)(de)巨龍“聚首”在一(yi)條(tiao)長達五十七(qi)米(mi)的(de)(de)排(pai)(pai)(pai)水(shui)渠(qu)(qu)(qu)邊。而排(pai)(pai)(pai)水(shui)渠(qu)(qu)(qu)道由一(yi)條(tiao)排(pai)(pai)(pai)水(shui)渠(qu)(qu)(qu)和長短不一(yi)、粗細不均的(de)(de)五角形排(pai)(pai)(pai)水(shui)管(guan)道共同構成。排(pai)(pai)(pai)水(shui)渠(qu)(qu)(qu)長達五十七(qi)米(mi)，寬(kuan)約(yue)一(yi)點八米(mi)，深約(yue)一(yi)點五米(mi)，在接納了(le)來(lai)自南(nan)方和東方的(de)(de)各個排(pai)(pai)(pai)水(shui)管(guan)道的(de)(de)污水(shui)之后，便向西北(bei)方向流去。這從(cong)側面表(biao)明(ming)了(le)西漢時期中國皇(huang)宮具有較高(gao)的(de)(de)建筑水(shui)平。
經過多年(nian)的(de)(de)(de)(de)考古(gu)勘探(tan)和發(fa)(fa)掘，長樂宮(gong)(gong)的(de)(de)(de)(de)布(bu)局、范圍(wei)日漸清晰，并(bing)且與文獻(xian)中的(de)(de)(de)(de)記(ji)載(zai)相互印證。整個宮(gong)(gong)城(cheng)占地(di)(di)面積(ji)約(yue)6平方公(gong)里，約(yue)占全城(cheng)總面積(ji)的(de)(de)(de)(de)六(liu)(liu)分之一，四周(zhou)建(jian)有圍(wei)墻。2003年(nian)發(fa)(fa)掘的(de)(de)(de)(de)四號宮(gong)(gong)殿(dian)(dian)（據(ju)考古(gu)研究為(wei)臨華殿(dian)(dian)）遺(yi)(yi)址有2000平方米(mi)，房(fang)子(zi)為(wei)半地(di)(di)穴(xue)式，鵝卵石鋪(pu)地(di)(di)后砂漿抹(mo)平地(di)(di)面，墻壁涂有白灰，并(bing)飾有奪目(mu)的(de)(de)(de)(de)彩繪壁畫(hua)，通(tong)道(dao)和臺(tai)階(jie)鋪(pu)有精美的(de)(de)(de)(de)印花磚(zhuan)，顯示出獨特(te)的(de)(de)(de)(de)審美取向。而后發(fa)(fa)掘出的(de)(de)(de)(de)五(wu)號宮(gong)(gong)殿(dian)(dian)遺(yi)(yi)址形制獨特(te)，遺(yi)(yi)址圍(wei)墻特(te)別厚。專(zhuan)家們推測這里就是(shi)用來儲(chu)藏冰的(de)(de)(de)(de)“凌室”，厚厚的(de)(de)(de)(de)墻壁有利于保持(chi)室溫，所藏之冰用來儲(chu)藏食物(wu)、防腐保鮮和降溫納涼。考古(gu)工作者發(fa)(fa)掘的(de)(de)(de)(de)長樂宮(gong)(gong)內規模(mo)較大的(de)(de)(de)(de)六(liu)(liu)號宮(gong)(gong)殿(dian)(dian)遺(yi)(yi)址，它(ta)的(de)(de)(de)(de)中心是(shi)一座大型(xing)夯土臺(tai)基，東西長約(yue)160米(mi)，南北殘寬(kuan)50余米(mi)，建(jian)筑(zhu)(zhu)布(bu)局有序、結構(gou)精巧(qiao)，出土了(le)大量的(de)(de)(de)(de)建(jian)筑(zhu)(zhu)構(gou)件。據(ju)考證，這處(chu)規模(mo)宏偉的(de)(de)(de)(de)建(jian)筑(zhu)(zhu)很可能就是(shi)長樂宮(gong)(gong)前殿(dian)(dian)遺(yi)(yi)址。除了(le)房(fang)屋、水(shui)井、院落外，緊貼夯土臺(tai)基的(de)(de)(de)(de)一條長34.29米(mi)、最寬(kuan)處(chu)1.9米(mi)的(de)(de)(de)(de)半地(di)(di)下通(tong)道(dao)引發(fa)(fa)了(le)諸(zhu)多猜想。有專(zhuan)家認為(wei)，這條地(di)(di)下通(tong)道(dao)就是(shi)皇(huang)宮(gong)(gong)中的(de)(de)(de)(de)秘道(dao)，是(shi)皇(huang)族們預(yu)防不測的(de)(de)(de)(de)安全通(tong)道(dao)。
長樂宮(gong)(gong)周圍筑(zhu)有(you)宮(gong)(gong)城，由于長樂宮(gong)(gong)是在秦興樂宮(gong)(gong)基礎上修建起來的缺乏系統規劃，平面不甚規整、為不規則的方(fang)形，尤其南宮(gong)(gong)墻凹凸(tu)轉折較多，宮(gong)(gong)城四面各設一座宮(gong)(gong)門(men)，東門(men)和(he)西門(men)外有(you)闕。
宮(gong)(gong)(gong)(gong)(gong)垣東西長(chang)(chang)2900米(mi)(mi)，南(nan)北(bei)(bei)寬2400米(mi)(mi)，周長(chang)(chang)10600米(mi)(mi)，占地面(mian)(mian)積約6平方(fang)公里，約占漢(han)長(chang)(chang)安(an)(an)城(cheng)總面(mian)(mian)積的(de)1/6。宮(gong)(gong)(gong)(gong)(gong)城(cheng)平面(mian)(mian)形制略呈(cheng)方(fang)形，南(nan)墻(qiang)(qiang)在覆盎(ang)門(men)西有(you)一曲折(zhe)，其(qi)余(yu)(yu)各(ge)墻(qiang)(qiang)都為(wei)(wei)直線(xian)。宮(gong)(gong)(gong)(gong)(gong)城(cheng)為(wei)(wei)夯筑(zhu)土墻(qiang)(qiang)，厚達20多米(mi)(mi)。宮(gong)(gong)(gong)(gong)(gong)墻(qiang)(qiang)四面(mian)(mian)各(ge)設一座宮(gong)(gong)(gong)(gong)(gong)門(men)，其(qi)中(zhong)東、西二(er)門(men)是主要通道(dao)，門(men)外(wai)有(you)闕(que)(que)樓稱為(wei)(wei)東闕(que)(que)和(he)西闕(que)(que)。南(nan)宮(gong)(gong)(gong)(gong)(gong)門(men)與覆盎(ang)門(men)南(nan)北(bei)(bei)相對。東、南(nan)兩面(mian)(mian)臨(lin)城(cheng)墻(qiang)(qiang)，西隔安(an)(an)門(men)大街(jie)與未(wei)央宮(gong)(gong)(gong)(gong)(gong)相望。長(chang)(chang)樂宮(gong)(gong)(gong)(gong)(gong)周回二(er)十余(yu)(yu)里，內有(you)14所(suo)宮(gong)(gong)(gong)(gong)(gong)殿(dian)(dian)(dian)(dian)，均坐北(bei)(bei)向南(nan)。其(qi)中(zhong)前殿(dian)(dian)(dian)(dian)位于南(nan)面(mian)(mian)中(zhong)部，前殿(dian)(dian)(dian)(dian)西側有(you)長(chang)(chang)信宮(gong)(gong)(gong)(gong)(gong)（即長(chang)(chang)信殿(dian)(dian)(dian)(dian)）、長(chang)(chang)秋殿(dian)(dian)(dian)(dian)、長(chang)(chang)定殿(dian)(dian)(dian)(dian)、永(yong)壽殿(dian)(dian)(dian)(dian)（即長(chang)(chang)壽殿(dian)(dian)(dian)(dian)）、永(yong)昌(chang)殿(dian)(dian)(dian)(dian)、永(yong)寧殿(dian)(dian)(dian)(dian)等；前殿(dian)(dian)(dian)(dian)北(bei)(bei)面(mian)(mian)有(you)大夏殿(dian)(dian)(dian)(dian)、臨(lin)華殿(dian)(dian)(dian)(dian)、宣(xuan)德殿(dian)(dian)(dian)(dian)、通光殿(dian)(dian)(dian)(dian)、高明殿(dian)(dian)(dian)(dian)、建(jian)(jian)始殿(dian)(dian)(dian)(dian)、廣(guang)陽殿(dian)(dian)(dian)(dian)、神仙殿(dian)(dian)(dian)(dian)、椒(jiao)房殿(dian)(dian)(dian)(dian)和(he)長(chang)(chang)亭(ting)殿(dian)(dian)(dian)(dian)等。另有(you)溫室(shi)(shi)殿(dian)(dian)(dian)(dian)、鐘室(shi)(shi)殿(dian)(dian)(dian)(dian)、月室(shi)(shi)殿(dian)(dian)(dian)(dian)以及秦始皇(huang)時在興樂宮(gong)(gong)(gong)(gong)(gong)中(zhong)建(jian)(jian)造的(de)高達40丈的(de)鴻臺。
長樂宮(gong)是中(zhong)國(guo)漢代的“三宮(gong)”之一。
漢高(gao)祖(zu)五年(nian)（公(gong)元前202年(nian)）九月，由丞相(xiang)蕭何主持在秦興(xing)樂宮基礎上開始營修。
漢(han)(han)高祖七(qi)年（公元(yuan)前(qian)200年）二月，長(chang)樂宮(gong)竣(jun)工(gong)。史載(zai)：（漢(han)(han)七(qi)年）二月，高祖自平城過趙、雒(luo)陽，至長(chang)安。長(chang)樂宮(gong)成，丞相已下徙治長(chang)安。
漢高祖九年（公元(yuan)前198年），朝廷遷往(wang)未(wei)央宮(gong)(gong)，長樂(le)宮(gong)(gong)改為(wei)太后住(zhu)所。太后所住(zhu)宮(gong)(gong)殿(dian)為(wei)長信宮(gong)(gong)，是長樂(le)宮(gong)(gong)建(jian)筑群中較重要的建(jian)筑物。
歲月靜好 
