inlet of the Bay of Bengal, between southeastern India and northern Sri Lanka and bounded on the south by Pāmban Island (India), Adam's (Rama's) Bridge (a chain of shoals), and Mannar Island (Sri Lanka). The strait is 40–85 miles (64–137 km) wide and 85 miles long. It receives several rivers, including the Vaigai (India), and it contains many islands of Sri Lanka. The port of Jaffna, the commercial centre for northern Sri Lanka, has trade with the state of Tamil Nādu, India. The southwestern portion of the strait is also called Palk Bay.