Chennai (formerly known as Madras) is the capital city of the Indian state of Tamil Nadu. Located on the Coromandel Coast off the Bay of Bengal, it is the biggest cultural, economic and educational centre in South India. Chennai is known as the "Detroit of South Asia" for its automobile industry. It is thefourth-largest city and fourth-most populous metropolitan area in india and 36th-largest urban area in the world. Chennai is one of the Indian cities most visited by foreign tourists, and is the 38th most visited city in the world. The Quality of Living Survey rated Chennai as the safest city in India.Chennai attracts 45 percent of health touristsvisiting India, and 30 to 40 percent of domestic health tourists. As such, it is termed "India's health capital".

For more info : Wikipedia - Chennai