The citadel is to the left, the Banyas Stream to the left. The Bradt guide explains that the citadel, which is on level ground and not on some height, was built where it is because in case of need the water of the river could be diverted into the moat (apart from the strategic advantage of controlling the waters anyhow). The river seems channelled now, and though running fast doesn't seem much, but it may well have been more like wild water.