Many of Chennai’s key attractions are clustered together, which makes covering all the major sites in one day relatively easy. Start your morning off in the Mylapore area, a walkable neighborhood that’s home to two of the city’s most significant religious sites: the 7th-century Kapaleeshwarar Temple and the 16th-century San Thome Cathedral. The former is the most important—or at least the most famous—Hindu temple in the city and features a gorgeous stacked tower covered with colorful carvings. The latter is best known for housing a relic of its namesake saint, Saint Thomas the Apostle.

 After visiting Mylapore, head north to Georgetown, an old colonial district best known for the 17th-century Fort St. George, built by the East India Company. Today it houses a museum of colonial artifacts. Also worth visiting is St. Mary's Church, the oldest British building in India and the oldest Anglican church east of Suez.

Devote your second day to exploring the ancient temples in the surrounding region, notably at Mahabalipuram (Mamallapuram) and Kanchipuram. Kanchipuram is home to some dozens of ancient temples built in the Dravidian style. The oldest, Kanchi Kailasanathar temple, dates back to the turn of the eighth century and features 58 shrines to Lord Shiva. The second-oldest temple here, Thiru Parameswara Vinnagaram, is dedicated to Lord Vishnu and is an important pilgrimage site for those following Vaishnava (Vishnu-centric) Hinduism.

Mahabalipuram is better known among international visitors than Kanchipuram, owing largely to its status as a UNESCO World Heritage Site. This beachfront group of monuments features a number of distinctive rathas (temples designed to resemble chariots) as well as rock-hewn bas reliefs and cave temples. Most of the temples here date to the sixth and seventh centuries, though archaeological excavations show evidence of earlier settlement.

Head out early and spend your final day in Pondicherry (aka Puducherry), a former French colony that still retains much of its original colonial look and feel. Pondicherry's French Quarter is a major draw for many travelers, known for its beautiful homes, French-designed parks, and peaceful beachfront promenade. There's also a famous temple here, Manakula Vinayagar Temple, dedicated to the elephant-headed god, Ganesh, the remover of obstacles.

 On the outskirts of Pondicherry, the township Auroville will be of interest to spiritual travelers. This spiritually driven international community was founded in the late 1960s by followers of Indian philosopher Sri Aurobindo. At the heart of the property is the Matrimandir, a golden-hued dome used for quiet contemplation, known as concentration. Day-trip visitors can view the dome from a special viewing point, as entering requires booking in person at least a day ahead of time.