 Some common techniques used to incorporate imagery of the Feathered Serpent into this architecture is relief carving, which involves “a sculpture with figures that protrude from a background while still being attached to it” and normally combined with tenoned heads, which are large pieces of stone carved but have a peg of sorts to insert them into the wall area, adding more depth and details to the architecture.Other Mesoamerican structures, such as the ones in Tula, the capital of the later Toltecs (950–1150 AD), also featured profiles of feathered serpents.The Aztec feathered serpent deity known as Quetzalcoatl is known from several Aztec codices, such as the Florentine codex, as well as from the records of the Spanish conquistadors.