Chinampa can be described as rectangular enclosures filled with mud and decaying matter that rise above the water surface. Another achievement that the Aztecs were known for was the discovery of popcorn, chewing gum and chocolate. Corn was the staple of the Aztec diet and was used to make tortillas and to adorn the hairstyles of the nobility and priests. Chewing gum was also discovered by the Aztecs; it came from the sap of the sapodilla tree and was called “chile” in Aztec society. Besides popcorn and chewing gum, chocolate was used by the Aztecs. Chocolate was considered very expensive and considered a luxury and often used as currency. It was commonly used during sacrificial events and reserved for the noble classes. Cacahuatl was an early form of chocolate drink used by the Aztecs.