TheTempleofHeavenwasinitiallybuiltinYongleyear18oftheMingDynasty(in1420).Situatedinthesouthernpartofthecity,itcoversthetotalareaof273hectares.WiththeadditionsandrebuildduringtheMing,QingandotherDynasties,thisgrandsetofstructureslookmagnificentandglorious,thedignifiedenvironmentappearssolemnandrespectful,itistheplaceforbothMingandQingDynasty'sEmperorstoworshipHeavenandprayforgoodharvest.ThenorthernpartoftheTempleiscircularwhilethesouthernpartissquare,implies"skyisroundandearthissquare"tobettersymbolizeheavenandearth.Thewholecompoundisenclosedbytwowalls,dividingthewholeTempleintoinnerandouterareas,withthemainstructuresenclosedintheinnerarea.ThemostimportantconstructionsaretheHallofPrayerforGoodHarvest,theCircularMoundAltar,ImperialHeaven,TheImperialVaultofHeaven,HeavenKitchen,LongCorridorandsoon,aswellastheEchoWall,theTriple-SoundStone,theSeven-StarStoneandothersofhistoricinterestandscenicbeauty.TheTempleofHeavenisacomprehensiveexpressionoftheuniqueconstructiontechniquesfromMingandQingDynasties,itisChina'smosttreasuredancientarchitecture,itisalsotheworld'slargestarchitecturalcomplexforworshipheaven.In1998,itwasincludedinthe"listoftheworldheritages"bytheUnitedNation'sEducational,ScientificandCulturalOrganization. 　　Doyouknow?TherearefourwonderfulsoundsintheTempleofHeaven!It'sworthyourtimetostudythefourwonderfulsounds. 　　1.TheechofromtheEchoWall-ThereisacircularwallaroundTheImperialVaultofHeaven,thisisthefamousEchoWall.Oneperson'smerewhisperatanypointclosetothewallcanbeheardclearlyontheothersideifyoudrawyourearclosetothewall,itissoclearthatitisliketalkingonthephone.Doyouwanttoknowwhy?Thisispossiblebecausethewallisroundandhermeticallyconstructedwithsmooth,solidbricks,sothesoundwavecantransmittotheothersideviatheextremelysmoothinnercircle. 　　2.ThesoundoftheDialogueStone-Ifyouspeakwhilestandingonthe18thstoneinfrontofTheImperialVaultofHeaven,thesoundcanclearlypasstothenortheastcornerofthenorthsidehallandthenorthwestofthewestsidehallthatareboth36metersaway.Thesoundcanbeheardjustaswellonthestonewhenspeakingfromthecornersofthesetwosidehalls,thisiswhatwecallthe"SoundoftheDialogueStone". 　　3.RepeatingsoundsoftheTriple-SoundStone-InfrontofthestepsleadingawayfromthehallistheTriple-SoundStone.Ifyoustandonthefirststoneandcalloutorclapyourhands,thesoundwillechoonce;onthesecondstone,thesoundwillbeheardtwice;andonthethirdstone,thesoundwillrepeatthreetimes.Henceitinheritedthename.Thisisbecausethedistancesthatthesoundwavereflectedfromtheroundwalltothestonearedifferent,thenumberofechoisalsodifferent.TakeaguesswhichflagstoneisatthecenteroftheEchoWall's?Thethirdone.Theechoactuallygetsrepeatedmorethan3times,it'sjustthesoundistooweaktobeheardafterthe4thecho. 　　4.ThehollowoftheHeaven'sCenterStone-ThereisastoneplateinthecenteroftheCircularMoundAltarcalledtheHeaven'sCenterStone.Shoutingaloudstandingabove,youwillhearthereverberationoftheecho.Thisisduetotherefractionofthesound. 　　BeijingMunicipality 　　AsthecapitalofthePeople