The Siq, a natural sandstone gorge that gently winds towards the ancient city of Petra for just over 2km until it opens on to the magnificent Treasury. A triumphal arch one spanned the entrance to the Siq, but this collapsed in 1895. On either side of the arch there were niches where busts of the king or emperor were placed. As you walk through, notice two water channels that run along each side; these held clay pipes that carried fresh water to the city from springs. Parts of the original paved road can be seen along the Siq. In its day, Petra was a bustling city that witnessed a constant procession of travelers, visitors and pilgrims, who passed along the same path you are on now. Keep your eyes open for the niches and god blocks (baetyls) carved throughout the Siq, which were there of protect those entering and leaving the city.