During the first three years of his campaign, Schliemann chose to work in a 40-m wide trench laid out N-S across the middle of the mound. This was a sondage 17 meters in depth (opened clear to the bedrock), an attempt to find the "City of Priam." The project resulted in the partial or total destruction of significant architectural structures belonging to the levels above, but at the base of the trench Schliemann laid bare the walls from the early period of Troy I (ca. 2920 BCE) that you see from here.