▁with ▁v ibr ant ▁colours . ▁For ▁instance , ▁O z zy ' s ▁art , ▁appearing ▁in ▁many ▁parts ▁of ▁Barcelona , ▁is ▁marked ▁by ▁bright ▁poster ▁designs , ▁while ▁the ▁artist ▁C 2 1 5 ▁produces ▁detailed ▁st enc illed ▁works . ▁ ▁Trad ition ▁ ▁The ▁most ▁notable ▁event ▁in ▁Gr à cia ▁is ▁the ▁Fest es ▁de ▁Gr à cia , ▁which ▁goes ▁on ▁for ▁eight ▁days ▁every ▁August . ▁The ▁largest ▁neighbourhood ▁festival ▁in ▁Barcelona , ▁the ▁F esta ▁Major ▁de ▁Gr à cia ▁began ▁in ▁ 1 8 1 7 ▁as ▁a ▁celebr ation ▁of ▁the ▁neighbourhood ▁itself ▁( at ▁the ▁time ▁still ▁an ▁independent ▁town ). ▁Gr à cia ' s ▁residents ▁comp ete ▁for ▁the ▁crown ▁of ▁best ▁street ▁or ▁square , ▁selecting ▁distinct ▁them es ▁and ▁extens ively ▁decor ating ▁in ▁Spanish ▁car n ival ▁style , ▁and ▁organ ised ▁by ▁a ▁number ▁of ▁local ▁associations . ▁The ▁selected ▁them es ▁range ▁from ▁scenes ▁of ▁nature , ▁to ▁wild ▁animals ▁and ▁cre atures , ▁to ▁characters ▁from ▁popular ▁culture . ▁ ▁The ▁Catal an ▁practice ▁of ▁cast ellers , ▁d ating ▁back ▁to ▁the ▁ 1 8 th ▁century , ▁is ▁also ▁en act ed . ▁The ▁inhabitants ▁of ▁V alls , ▁a ▁tiny ▁town ▁located ▁on ▁the ▁out sk ir ts ▁of ▁Barcelona , ▁initi ated ▁this ▁tradition ▁of ▁human ▁to wers , ▁which ▁became ▁a ▁compet itive ▁sport . ▁The ▁original ▁structure ▁was ▁accompanied ▁by ▁a ▁traditional ▁fol kl ore ▁dance ,