 These incidents appear to have prompted the massive strengthening and expansion of the fortifications in various sites. In some cases, arrangements were also made for the creation of subterranean passages which led to underground cisterns. Tiryns, Midea and Athens expanded their defences with new cyclopean-style walls. The extension program in Mycenae almost doubled the fortified area of the citadel. To this phase of extension belongs the impressive Lion Gate, the main entrance into the Mycenaean acropolis.
