BigBenisthenicknameforthegreatbelloftheclockatthenorthendofthePalaceofWestminsterinLondonandisgenerallyextendedtorefertotheclockortheclocktoweraswell.Itisthelargestfour-facedchimingclockandthethird-tallestfree-standingclocktowerintheworld.Itcelebratedits150thanniversaryon31May2009,duringwhichcelebratoryeventstookplace.Theerectingofthetowerwascompletedon10April1858.TheclocktowerhasbecomeoneofthemostprominentsymbolsofbothLondonandEngland,oftenintheestablishingshotoffilmssetinthecity.