The ride from Chennai to Kanchipuram passes by newly built factories for cell phones and cars as well as by rice and sugarcane fields, both of them next to the smooth national highway, NH-4. You'll also go through villages at very close range, with houses right on the roadside. Don't be surprised if you have to stop for goats crossing the road. The former capital of the ancient Pallavas, Kanchipuram holds the remains of three great dynasties—Pallava, Chola, and Vijayanagar—that for centuries weathered internal conflict and external trade but never northern invasion. The dynasties merely jostled each other, building ever greater shrines to their developing and intertwining sets of deities. Today, Kanchipuram, nicknamed the Golden City of 1,000 Temples (as well as "Kanchi"), is one of the seven holy pilgrimage sites for Hindus, with some temples to Vishnu and a majority devoted to Shiva. Through the diversity of building styles here, you can trace the development of Dravidian temple architecture from the 8th century to the present.
The temples covered below are some of the more famous of the nine major ones in Kanchi, but there are plenty of others to explore. All of them are generally open from 8:30 AM to 12:30 PM and then open again 4 to 8 PM. It's usually best to make an early start of it. Many of the temples have their own elephants (relating to the elephant-headed god Ganesh), who patiently stand by the main gopuram to bless anyone who makes a contribution (usually a one- or two-rupee piece). The elephant takes the money in its trunk, gives it to its minder, and then put its trunk on the blessee's head. It all makes for a fun and possibly beneficial photo-op.