Cutting through the Arad citadel: An imaginary slice through Tel Arad provides a view of the fortress’s complex stratigraphy, or layers of occupation. The colors used to identify archaeological periods are the same colors used on the plan and on the individual fortresses.

Many of the structures, including the altar and the outer walls, continued in use during more than one period of the fortress’s history. During periods when the citadel was abandoned, loess (fine blown sand) accumulated to a thickness of up to 16 inches (40 cm) between strata.

On the far right and left the glacis slopes up to the city wall, supported at its lowest end by a revetment wall. The water channel passes below the western revetment wall, left, the glacis and the city wall before opening into a large cistern beneath the city.