While only one tumulus is found within the study area itself - the Demirtas in the northwest - a number of
other tumuli are present in very close proximity to, although falling just outside of the region in question. These
include the Cayirkoy tumulus on the Cayirkoy Plain, which is separated from the Bursa Plain by the 100-150 m
high Neogene hills at its western end; the Aktopralik tumulus on the ridge near Akcalar village at the eastern end
of Ulubat Lake which is to the west of the study area; and finally the Marmaracik, Mentese and Yenisehir II
tumuli separated from the Bursa Plain by the Turan village threshold. These tumuli are located in close
proximity to the plains on or nearby highly fertile alluvial soils, indicating that settlements have been established
in these areas since ancient times.