The name Chichen Itza probably derives from a large sinkhole known as the mouth of the well of the Itza into which the Maya threw offerings of jade and gold, and as the presence of bones testifies, human sacrifices. The early history of the site is still not clear but settlement was certain by the Classic period (250-900 CE). With the collapse of Teotihuacan migrants may have come to the site from varying parts of Mesoamerica and it seems likely there was contact with the Itza a Maya group. A second period of construction seems to coincide with influence from the Toltec civilization. That Chichen Itza was a thriving trade centre with a port at Isla Cerritos is evidenced by finds of goods from elsewhere in Central America for example, turquoise from the north gold disks from the south and obsidian from the Isthmus of Tehuantepec. The cultivation of cacao is known and the city may have controlled the lucrative salt beds on the nearby northern coast.