another circuit completed , and finding himself on the south side of the building , facing towards the larger expanse of yanggak island , the yanggak bridge and the railway line - the wendelson building having been constructed on the northern end of the island - martin momentarily strayed away from the racing line that he had been religiously maintaining - sticking as close as possible to the reassuring solidity of the buildings external wall - and edged towards the parapet of the ramp , in order to look directly down at the ground at the base of the massive tower .