The megalithic monuments are one of the earliest existing architectural legacy of the whole of South India in general and Tamil Nadu in particular. The kaleidoscopic variety of megalithic monuments, which found extensively almost all over South India during the Iron Age and Early Historic period, are not only the prolific cultural inheritance of South India, but also exhibit a colourful picture of architecture and religious practice of our predecessors. They are usually large in number and must have required considerable time and labour for their construction. The construction of these monuments was a well-organized feat of engineering and coordination of manpower. Since Sengalur and its surrounding has extensive megalithic monuments of different varieties, the site was chosen for excavation to study the mechanism involved and method of construction of different types of early edifices in one place and to have a comparative study of them. Different types of megalithic monuments, including the peculiar variety of Rectangular Stone Enclosure type were excavated systematically and the book dealt in details about the excavations and the unique finding in them along with elegant line drawings and photographs. Meticulous analysis has been made to understand the human resource management, equipment used, volume of materials and time involved in the execution of work and stages of construction and also the associated culture of these monuments. The habitation site possibly associated with the megalithic people was identified in the nearby area after an extensive exploration and excavation was taken up in the area to comprehend the socio-economic condition of the megalithic people. The book incorporates the details of the excavation in the habitation site and also provide a precise cultural sequence of this area for the first time, as there is no systematic study of it has been carried out in this area so far.