▁to ▁the ▁con str icted ▁site ▁on ▁which ▁the ▁theatre ▁was ▁built , ▁as ▁Lloyd ▁notes , ▁ ▁" the ▁stage ▁of ▁the ▁London ▁Col ise um ▁was ▁also ▁on ▁a ▁vast ▁scale ; ▁ 5 5 ▁feet ▁wide ▁by ▁ 9 2 ▁feet ▁deep ". ▁The ▁stage ▁is ▁not ▁ra ked . ▁It ▁has ▁the ▁wid est ▁pro sc enium ▁arch ▁in ▁London ▁and ▁was ▁one ▁of ▁the ▁first ▁to ▁have ▁electric ▁light ing . ▁It ▁was ▁built ▁with ▁a ▁triple ▁revol ving ▁stage , ▁although ▁this ▁was ▁rarely ▁used . ▁The ▁Col ise um ▁was ▁designed ▁to ▁seat ▁ 2 , 3 5 8 ▁people ▁on ▁four ▁levels . ▁ ▁As ▁such ▁it ▁is ▁the ▁largest ▁of ▁all ▁London ' s ▁the at res . ▁ ▁The ▁theatre ▁retain s ▁many ▁of ▁its ▁original ▁features ▁and ▁was ▁given ▁a ▁Gra de ▁II * ▁listed ▁building ▁by ▁English ▁Heritage ▁in ▁September ▁ 1 9 6 0 . ▁Prior ▁to ▁Sad ler ' s ▁Well s ▁Opera ▁Company ▁taking ▁over ▁the ▁Col ise um ▁in ▁ 1 9 6 8 , ▁the ▁house ▁was ▁" fully ▁restored , ▁re decor ated , ▁and ▁a ▁large ▁or chestra ▁pit ▁installed ". ▁It ▁re open ed ▁on ▁ 2 1 ▁August ▁ 1 9 6 8 , ▁with ▁a ▁production ▁of ▁the ▁opera ▁Don ▁Giovanni . ▁ ▁Another ▁extensive ▁renov ation ▁took ▁place ▁between ▁ 2 0 0 0 ▁and ▁ 2 0 0 4 . ▁when ▁the ▁design ▁team ▁included ▁the ▁architect s ▁R