With reference to ancient South India, Korkai, Poompuhar and Muchiri were well known as

Korkai, Poompuhar, and Muchiri were prominent ancient port cities in South India during the Sangam period (c. 3rd century BCE to 3rd century CE). They played a vital role in maritime trade between India and the Roman Empire, as well as Southeast Asia.

• Korkai: Located at the mouth of the Thamirabarani River in present-day Tamil Nadu, it was an important port of the Pandya dynasty. It was particularly famous for its pearl fishery.
• Poompuhar (also known as Kaveripattinam): Situated at the mouth of the Kaveri River, it was the chief port of the Early Cholas. It is vividly described in Sangam literature (like Silappadikaram) as a bustling hub of international trade.
• Muchiri (Muziris): Located on the Malabar Coast (modern-day Kerala), it was a major port of the Chera dynasty. It was the primary center for the pepper trade with the Roman Empire.

Note: In Sangam literature, the term 'Puhar' specifically refers to a river mouth or a harbor town where goods were discharged.