 The <unk> of the <unk> is located below the floor of the cathedral beneath the Altar of the Kings . The entrance to the crypt from the cathedral is guarded by a large wooden door behind which descends a winding yellow staircase . Just past the inner entrance is a <unk> @-@ style stone skull . It was incorporated as an offering into the base of a <unk> to Juan de Zumárraga , the first archbishop of Mexico . Zumárraga was considered to be a benefactor of the Indians , protecting them against the abuses of their Spanish overlords . There is also a natural @-@ sized sculpture of the archbishop atop the <unk> . 
