The walls extend to the entire area of the top of the hill. Their bases survive throughout all of their length, and their height in some places reaching 7 meters, slightly below the original height, which is estimated at 9–10 m. The walls are quite thick, usually 6 meters, and up to 17 m at the points where the tunnels pass through. A strong transverse wall separates the acropolis into two sections -the south includes the palatial buildings, while the northern protects only the top of the hill area. In this second section, which dates to the end of the Mycenaean era, small gates and many tunnels occasionally open, covered with a triangular roof, which served as a refuge for the inhabitants of the lower city in times of danger.