Chennai is situated on the north-east end of Tamil Nadu on the coast of Bay of Bengal. It lies between 12° 9' and 13° 9' of the northern latitude and 80° 12' and 80° 19' of the southern longitude at an average altitude of 6 metres from the sea level. It covers a total area of 174 sq km that is spread irregularly in the northeast corner of Tamil Nadu.
There are five administrative divisions in Chennai namely the Egmore-Nungambakam, Fort Tondiarpet, Mambalam - Guindy, Mylapore-Triplicane, and Perambur - covers 1,177 sq. km which is divided into four parts: North, Central, South, and West.
Metropolitan area of Chennai consists of three districts namely Chennai city and the districts of Kanchipuram and Thiruvallur. On the basis of geology the city has three regions: sandy regions, clayey regions and hard-rock regions. The soil of Chennai comprises of clay, shale and sandstone. The city’s clayey areas include Transport Nagar, West Mambalam, Anna Nagar, Kolathur and Virugambakkam. Chennai falls in the seismic zone III where an earthquake risk is moderate. But the city comes under the “Cyclonic Zone” where the possibility of frequent cyclones is very high.