The city had been built on an island in the middle of a salt lake, reached by three causeways of masonry four or five miles long and twenty or thirty feet wide. At the end near the city each causeway had a wooden drawbridge. There were paved streets and water-ways. The houses, built around large court-yards, were of red stone, sometimes covered with white stucco. The roofs were encircled with battlements and defended with towers. Often they were gardens of growing flowers. In the center of the city was the temple enclosure, surrounded by an eight-foot stone wall. Within this were a score of teocallis, or pyramids flattened at the top, the largest, that of the war-god, being about a hundred feet high. Stone stairs wound four times around the pyramid, so that religious processions appeared and disappeared on their way to the top. On the summit was a block of jasper, rounded at top, the altar of human sacrifice. Near by were the shrines and altars of the gods. Outside the temple enclosure was a huge altar, or embankment, called the tzompantli, one hundred and fifty-four feet long, upon which the skulls of innumerable victims were arranged. The doorways and walls everywhere were carved with the two symbols of the Aztec religion--the cross and the snake. Among the birds in the huge aviary of the royal establishment were the humming-birds which were sacred to one of the most cruel of the gods, and in cages built for them were the rattlesnakes also held sacred. Flowers were everywhere--in garlands hung about the city, in the hands of the people, on floating islands in the water, in the gardens blazing with color. The Spanish strangers were housed in a great stone palace and entertained no less magnificently than the gifts of the Emperor had led them to expect. The houses were ceiled with cedar and tapestried with fine cotton or feather work. Moteczuma's table service was of gold and silver and fine earthenware. The people wore cotton garments, often dyed vivid scarlet with cochineal, the men wearing loose cloaks and fringed sashes, the women, long robes. Fur capes and feather-work mantles and tunics were worn in cold weather; sandals and white cotton hoods protected feet and head. The women sometime used a deep violet hair-dye. Ear-rings, nose-rings, finger-rings, bracelets, anklets and necklaces were of gold and silver.