SanFrancisco,officiallytheCityandCountyofSanFrancisco,isthefourthmostpopulouscityinCaliforniaandthe13thmostpopulouscityintheUnitedStates,witha2010estimatedpopulationof805,235.Theonlyconsolidatedcity-countyinCalifornia,itencompassesalandareaof46.7squaremiles(121km2)onthenorthernendoftheSanFranciscoPeninsula,givingitadensityof17,243people/mi²(6,655people/km²).Itisthemostdenselysettledlargecity(populationgreaterthan200,000)inthestateofCaliforniaandthesecond-mostdenselypopulatedlargecityintheUnitedStates.SanFranciscoisthefinancial,cultural,andtransportationcenteroftheSanFranciscoBayArea,aregionofmorethan7.4millionpeoplewhichincludesSanJoseandOakland.

　　In1776,theSpanishestablishedafortattheGoldenGateandamissionnamedforFrancisofAssisionthesite.[17]TheCaliforniaGoldRushin1848propelledthecityintoaperiodofrapidgrowth,increasingthepopulationinoneyearfrom1,000to25,000,[18]andthustransformingitintothelargestcityontheWestCoastatthetime.Afterthree-quartersofthecitywasdestroyedbythe1906earthquakeandfire,[19]SanFranciscowasquicklyrebuilt,hostingthePanama-PacificInternationalExpositionnineyearslater.DuringWorldWarII,SanFranciscowastheportofembarkationforservicemembersshippingouttothePacificTheater.[20]Afterthewar,theconfluenceofreturningservicemen,massiveimmigration,liberalizingattitudes,andotherfactorsledtotheSummerofLoveandthegayrightsmovement,cementingSanFranciscoasacenterofliberalactivismintheUnitedStates.

　　Today,SanFranciscoisapopularinternationaltouristdestination,[21]renownedforitschillysummerfog,steeprollinghills,eclecticmixofVictorianandmodernarchitectureanditsfamouslandmarks,includingtheGoldenGateBridge,cablecars,andChinatown.Thecityisalsoaprincipalbankingandfinancecenter,andthehometomorethan30internationalfinancialinstitutions,[22]helpingtomakeSanFranciscoeighteenthplaceintheworld'stopproducingcities,ninthintheUnitedStates,andfifteenthplaceinthetoptwentyGlobalFinancialCenters.