The region known as the Riviera Maya was an important commercial and religious center for the ancient Maya during the Post-Classic Period (1000-1550 A.D.). Tulum, a Mayan fortress that looms over the Caribbean sea, is the most impressive site from this era, but there were other important towns such as Xaman-Ha (today Playa del Carmen), Xcaret (known by the Mayans as the port of Pole) and Xel-Ha, which was the first European settlement in the peninsula. Further inland is Coba, a city which had 50,000 inhabitants during the Classic Period (300-1000 A.D.).