The island is about 48 km (30 miles) north-south and 16 km (10 miles) east-west, and is the largest Atlantic island of Mexico. It is about 20 km (12 miles) from the mainland, and some 60 km (36 miles) south of Cancún. The vast majority of the population of Cozumel lives in the town of San Miguel (pop. 71,401 in 2005), which is on the western shore. The rest of the island is low, flat, and densely vegetated.