2 4 4 ▁steps ▁from ▁old ▁wooden - ste pped ▁es cal ators ▁at ▁W yn yard ▁railway ▁station , ▁Sydney , ▁Australia , ▁were ▁" ref ashion ed ▁into ▁a ▁so aring ▁cr iss cross ing ▁t angle ▁rem in is cent ▁of ▁an ▁E scher ▁puzz le " ▁named ▁' Inter loop ', ▁designed ▁by ▁local ▁artist ▁Chris ▁Fox ▁and ▁h anging ▁from ▁a ▁ce iling ▁above ▁one ▁of ▁the ▁new ▁sets ▁of ▁es cal ators . ▁ ▁References ▁to ▁other ▁works ▁ ▁The ▁Doctor ▁Who ▁episode ▁" Cast ro val va " ▁takes ▁its ▁name ▁from ▁E scher ' s ▁early ▁l ith ograph ▁of ▁the ▁same ▁name , ▁though ▁E scher ' s ▁view ▁of ▁Castro val va ▁has ▁none ▁of ▁the ▁par ado x ical ▁elements ▁of ▁his ▁later ▁works ▁to ▁which ▁the ▁setting ▁of ▁the ▁episode ▁could ▁more ▁readily ▁be ▁compared . ▁ ▁She ila ▁Ch andra ▁included ▁a ▁piece ▁called ▁" E scher ' s ▁Tri angle " ▁on ▁her ▁CD ▁Ro ots ▁and ▁W ings ▁- ▁the ▁title ▁refers ▁to ▁E scher ' s ▁use ▁of ▁the ▁Pen rose ▁triangle ▁in ▁pictures ▁like ▁Water fall . ▁ ▁A ▁com ic ▁c ros so ver ▁between ▁Mike ▁All red ' s ▁Mad man ▁and ▁Bern ie ▁M ire ault ' s ▁The ▁Jam , ▁features ▁E scher ▁as ▁a ▁central ▁character ▁when ▁the ▁two ▁characters ▁enter ▁into ▁an ▁alternate ▁universe ▁created ▁by ▁a ▁somewhat ▁god like ▁E scher , ▁based ▁on ▁many ▁of ▁his ▁works .