Also called pylon tombs or Assyrian tombs. The walls are often slightly tapered backwards and inwards at the top, reminiscent of pylons of Egyptian sacred buildings. The façade is decorated with one or two friezes of stepped merlons (crowsteps) and a half merlon at each corner with relief mouldings below and above.
The frieze of stepped crenellations was already common in the brickstone architecture of Mesopotamia in the 3rd millennium BC and in Persian art of the 6th/5th century BC. Direct models of the Nabataeans could have been the crenellated friezes of Phoenician-Hellenistic buildings in the necropolis of Amrit (on the Levantine Mediterranean coast in present-day Syria), which were also carved from the rock.