The Palk Strait connects the Arabian Sea and Palk Bay in the Bay of Bengal, and lies between the state of Tamil Nadu in India and the Mannar district of the Northern Province of Sri Lanka. The Strait is 53 to 82 kilometres wide. There are several rivers that flow into the Strait, including the Vaigai River of Tamil Nadu.

At the southern end of Palk Bay lies a chain of low islands and reef shoals that are collectively called Adam's Bridge, but are also popularly known as "Ram Setu", meaning ‘the Bridge of Rama’. This is so called because in Hindu mythology, the epic Indian poem the Ramayana, written thousands of years ago recounts how Rama, aided by an army of vanaras, assembled a bridge of stones stretching across the sea to Lanka to rescue his wife Sita from the Asura King Ravana. This chain of islands extends from Pamban or Rameswaram Island in Tamil Nadu to Mannar Island in Sri Lanka. Pamban Island is connected to the Indian mainland by the Pamban Bridge.

The Strait’s shallow waters and reefs make it cumbersome for large ships to navigate, therefore they are obliged to travel around Sri Lanka, but fishing boats and small craft dealing in coastal trade have passed through the strait for centuries.