Tulum is a post-classic town, probably founded in around 1200, perhaps as a port for the town of Coba, to which it was connected by a causeway. It was clearly of strategic significance and was surrounded by defensive walls with watchtowers at the corners. The buildings are not spectacular but the seaside location and spacious layout makes it an agreeable place to visit, and it was crowded by day-trippers from the Maya Riviera. The dominant building is the Castillo, perched on cliffs above the sea and the buildings bear marks of Toltec influence. There is a temple to the Descending God, probably personifying the setting sun, and it is appropriate that this, the last of our Maya sites dates from the twilight of Maya civilisation. It was viewed from the sea by the Spanish explorer Grijalva in 1518 and a member of the expedition described its brightly painted buildings and the fire burning on top of one of the buildings. The site continued to be occupied by the Maya until the end of the 16th century.