By the time the Spanish arrived, Culhuacán was no longer an important city; rather it had been eclipsed by Iztapalapa as one of the Aztec royal town, chosen as such due to its defensive position. At that time, the area has about 10,000 inhabitants dedicated to chinampa agriculture and the raising of fish and birds. A causeway linking Iztapalapa and Tenochtitlan was one of the most important roads in the area. The construction of this causeway began in 1429 under Itzcoatl, using labor from peoples from the south of the valley such as the Xochimilcas. It consisted of artificial land built up from the shallow lake bottom, rising about a meter and a half over the lake's surface and extending for about . It was wide enough for horses to cross in pairs. The causeway was divided by a fort called Xoloc, made of stone with towers, merlons and gates to control entrance and exit. This causeway also had a branch leading to Coyoacán. Its ruler was Cuitláhuac, born in 1476 as younger brother of Moctezuma Ilhuicamina and son of Axayacatl. Cuitláhuac received the Spanish in Iztapalapa before they went onto Tenochtitlan. They met in a garden which most Aztec lords had as a refuge and to demonstrate culture. In the center of the garden was a large palace made of sandstone and fine woods such as cedar.