City defenses, Hattusas
Fragments of the 3.5km/2 mile-long city defenses of Hattusas are still visible in many places. For the most part these took the form of an 8m/26ft-wide cyclopean wall, with massive bastions and posterns protected by towers and gate chambers. Clever use was made of the geography of the site by incorporating various rocky outcrops; elsewhere the wall was artificially raised upon great earthen ramparts. At Yerkapi, the most elevated point of the upper city, the rampart is 80m/262ft wide at the base and about 20m/65ft high. All these defense works were completed in two phases in the late 14th and late 13th centuries. During the second phase the wall, previously about 5m/16ft wide, was strengthened by the addition of a another wall set about 4m/13ft in front of the towers of the original one. This new wall was flanked by bastions 6m/19ft wide and 4m/13ft deep, leaving a gap between it and the towers of the main wall. All the walls were built of clay bricks on a foundation of carefully dressed stone. Apart from the Sphinx Gate the design of the gates followed the same pattern - a small, partially enclosed, forecourt in front of the gate, and a gate chamber with parabolic arched entrances front and rear, protected by towers either side.