The island is about 48 km (30 mi) north-south and 16 km (10 mi), and is the largest island of Mexico. It is about 20 km (12 mi) from the mainland, and some 60 km (36 mi) south of Cancun. Nearly everybody in Cozumel lives in the town of San Miguel (pop. est. 90,000 in 2003), which is on the western shore. The rest of the island is low, flat, and densely vegetated.
The Maya are believed to have first settled Cozumel by the early part of the 1st millennium AD, and older Preclassic Olmec artifacts have been found on the island as well. The island was sacred to Ix Chel, the Maya Moon Goddesss, and the temples here were a place of pilgrimage, especially by women desiring fertility. There are a number of ruins on the island, most from the Post-Classic period. The largest Maya ruins on the island were bulldozed to make way for a airplane runway during World War II. The first Spanish visitor was Juan de Grijalva in 1518, and in the following year Hernan Cortes came with a fleet and destroyed many Maya temples. Some 40,000 Mayans lived on the island then, but smallpox devastated them and by 1570 only 30 were left alive. In the ensuing years Cozumel was nearly deserted, used as a hideout by pirates from time to time. In 1848, the War of the Castes resulted in resettlement by refugees escaping the tumult.
In the 1960s, Jacques Cousteau discovered the extent and beauty of the coral reefs around Cozumel and publicized it as one of the great dive locations of the world.
In the late 1970s a much enlarged airport was built, capable of handling jet aircraft and international flights. This resulted in much greater tourism to Cozumel.
Diving is still a primary draw, but Cozumel built a deepwater pier in the 1990s (causing some damage to the reefs) so that cruise ships could easily dock there, and it is now a regular stop on cruises in the Caribbean.