Cozumel is Mexico's largest Caribbean island, and is in the state of Quintana Roo, Mexico. Cozumel is approx. 30 miles long x 10 miles wide (or 48km x16 km) and sits off the Eastern coast of Mexico’s Yucatan Peninsula, in the Caribbean Sea. You can get to Cozumel in an hour’s drive south of Cancun to the popular beach town of Playa del Carmen, and then take a 40-minute ferry from Playa del Carmen to Cozumel island.