Lalmai an isolated hill range, west of Comilla town, about 8 kilometres long and at its widest point 4.8 kilometres wide. The tract shows a spread of rolling uplands intersected by a number of depressions. Its highest peaks are over 46 meters. The northern portion of the hill range is called Mainamati hills, while the southern part is known as Lalmai hills. Fragments of fossil wood are more plentiful in the southern part of the hill range than the northern one.

Archaeological expeditions were conducted in the Lalmai hill range in April 1989 and in July 1991. These resulted in the discovery of 11 prehistoric sites: Lalmai-1, Lalmai-2, Lila Mura and Takka Mura, Maharam Alir Bari, Tipra Mura, Mandara Mura, Maidhar Mura, Membarer Khil, Meher Kuler Mura, Takka Mura-2 and Sardarer Pahar. The artifacts obtained from these sites are made of fossil wood. They include chopping tools (3), handaxes (6), cleavers (4), adzes (12), a chisel (1), celts (2), blades/bladelets (46), scrapers (98), points (50), borers (9), burins (4), utilised flakes (124), flakes/cores (33) and chips (43). The above list of artifacts suggests that they originate from a Neolithic industry. A small-scale excavation was carried out in 1991 at the slope of Lalmai -1 in an area measuring 1.5 × 1 m. The excavation yielded a few pieces of potsherds along with fossil wood artifacts. The pottery - a diagnostic trait of Neolithic culture - found at the site is in a very decayed condition and devoid of any design. [MM Hoque]