▁struct ural ▁steel . ▁The ▁building ▁not ▁only ▁has ▁minimal ▁impact ▁upon ▁the ▁re lic s , ▁but ▁also ▁provides ▁increased ▁visual ▁and ▁physical ▁access ▁through ▁interior ▁building ▁void s , ▁two ▁re construct ed ▁historic ▁lan ew ays ▁( C rib bs ▁and ▁Car ah ers ▁L anes ), ▁interpret ative ▁works ▁and ▁arte fact ▁displays ▁in ▁the ▁new ▁building . ▁ ▁Cond ition ▁▁ ▁As ▁at ▁ 2 7 ▁July ▁ 2 0 0 7 , ▁Ass ess ment ▁Cond ition : ▁Minor ▁Dist urb ance , ▁Arch ae ological ▁Ex c av ation ▁of ▁ 7 0 % ▁of ▁resource , ▁ 1 9 9 4 . ▁Ass ess ment ▁Bas is : ▁Ex c av ations ▁in ▁ 1 9 9 4 ▁revealed ▁an ▁exception ally ▁well ▁preserved ▁resource ▁with ▁over ▁ 7 5 0 , 0 0 0 ▁arte fact s ▁recovered . ▁Site ▁pres erves ▁approximately ▁ 6 0 % ▁of ▁its ▁pre - 1 8 3 0 ▁resource ▁and ▁ 1 0 0 % ▁of ▁remains ▁of ▁eight ▁terra ces ▁built ▁in ▁the ▁ 1 8 4 0 s – 1 8 5 0 s ▁and ▁demol ished ▁. ▁Investig ation : ▁Full ▁scale ▁exc av ation , ▁ 1 9 9 4 . ▁Other ▁smaller ▁scale ▁exc av ations ▁have ▁been ▁carried ▁out ▁by ▁the ▁University ▁of ▁Sydney ▁Summer ▁School ▁in ▁ 2 0 0 5 ▁& ▁ 2 0 0 6 . ▁ ▁The ▁site ▁was ▁subject ▁to ▁arch ae ological ▁investigation ▁in ▁