This text is a fragment of a guidebook to Hattusa: "The Secrets of Hattusa".

Between 2003 and 2005, a 65-meter-long section of the fortification walls of Hattusa was rebuilt by the German Archaeological Institute (DAI). As a result, three 7 to 8-meter-high wall sections and two 12 to 13-meter-high defensive towers were reconstructed. The Japanese company JT International supported the project as a sponsor.

The archaeologists worked in the spirit of experimental archaeology with historical materials and historical processes. They made 64,000 clay bricks, using 2,700 tons of clay soil, 100 tons of straw, and around 1,500 tons of water. In addition, around 1,750 tons of earth rubble were required for filling and building ramps, as well as logs for constructing the tower floors. The usual dimensions of the square clay bricks (around 45 by 45 by 10 centimetres, around 34 kilograms) were known, as some bricks had survived intact from the Hittite times. Clay models of the city wall, which the Hittites had attached to the edge of large cult vases as decoration, served as a guide for the design.

On average, 27 workers were at work for about 11 months. The workload totalled 6,772 man-days, although excavators, tractors, and trucks were used to procure the material in order to keep costs within limits. How high the corresponding effort was in the times of the Hittites, who worked without the support of machines, could only be estimated. Extrapolations showed that the Hittites had to employ around a thousand workers if they wanted to construct one kilometre of city wall per year. The archaeologist responsible for the project, Jürgen Seeher, assumed that it had mainly been prisoners who built the old city walls. Several cuneiform texts report that the kings of the Hittites brought thousands of people back as booty from their military campaigns in order to compensate for the chronic shortage of workers.

When calculating the historical labour requirements, longer breaks during the winter months were taken into account. Mud brick production in Central Anatolia is only possible in summer, when it is warm enough and there is no rain, for example from mid-June to mid-September. The experimental project also includes ongoing observation of the reconstructed walls to see how the weather affects the structure and how often the plaster, which protects the mud bricks but is washed away by rain over time, needs to be repaired.