It is the ancient main entrance leading to the city of Petra, starts at the Dam and ends at the opposite side of the vault, a split rock with a length of about 1200m and a width of 3 to 12m, and height up to about 80m; most of the rock is natural and another part was sculptured by the Nabataeans. The Siq, the main road that leads to the city, starts from the Dam and ends at the Treasury. It is a rock canal that measures 160 meters in length, 3 to 12 meters in width and reaches up to 80 meters in height. The main part of the Siq is created by natural rock formation and the rest is carved by the Nabataeans.

At the beginning of the Siq, one can still view the remains of the city’s gate. On both sides of the Siq, there are channels to draw water from Wadi Musa (the Valley of Moses), from outside the city to the inside.

From the right, it is evident that the water flowed through pottery pipes but the left channel is carved from the rock and covered with panels of stone, and there are spaces in place to filter water. At the start of the Siq the original Nabataean dams are visible, and these prevented the flooding in the Siq, and collected water for use. The floor of the Siq is paved with stone slabs, part of which can be viewed in its original location.

Aspects of the Siq were decorated with Nabataean sculptures, mostly representing gods. It is believed that the statues of gods and their sculptures were situated very close and even adjacent to the channels due to the Nabataean belief that water was sacred. In addition, on the left side there are idols called Sabinos Statues.