Ur-Nammu's ziggurat at Ur was designed as a three-stage construction, but today only two of these survive. This entire mudbrick core structure was originally given a facing of baked brick envelope set in bitumen, 2.5 m on the first lowest stage, and 1.15 m on the second. Each of these baked bricks were stamped with the name of the king. The sloping walls of the stages were buttressed. The access to the top was by means of a triple monumental staircase, which all converges at a portal that opened on a landing between the first and second stages. The height of the first stage was about 11 m while the second stage rose some 5.7 m. Usually, a third stage is reconstructed by the excavator of the ziggurat (Leonard Woolley), and crowned by a temple. At the Chogha Zanbil ziggurat, archaeologists have found massive reed ropes that ran across the core of the ziggurat structure and tied together the mudbrick mass.