How did the Hittites use Hattusa’s landscape to defend their capital?

The Hittites strategically utilized the natural landscape of Hattusa to bolster the defense of their capital, which was situated on a mountain slope between two deeply cut streambeds. By filling the angle between these converging watercourses, the city gained natural protection from the terrain.1

During the New Kingdom, the Hittites further integrated the landscape into their fortification system by extending the city walls to include the southern hills. This expansion allowed them to implement sophisticated defensive features:1

• Topographical Barriers: The city was protected against the southern hills by a deep fosse (moat) and a high earth rampart that carried the city wall.1
• Engineered Slopes: Defenders utilized a paved glacis—a defensive slope—along with a corbeled tunnel known as Yerkapu (Ground Gate) and strategic flights of steps to manage the steep terrain.1
• Citadel Placement: The city’s high citadel, Büyükkale, was positioned on a rocky outcrop, providing a naturally elevated and secure acropolis.21

These natural advantages, combined with massive cyclopean masonry walls, made the capital a formidable stronghold.21