The Yaxchilan Lintels. Lintel 15. Structure 21. Carved limestone lintel with glyphs and a scene representing Lady Wak Tuun, during a bloodletting rite. She is carrying a basket with the paraphernalia used for auto-sacrifice: stingray spine, a rope and bloodied paper. The vision serpent appears before her springing from a bowl set before her which also contains strips of bark-paper. Late Classic Maya, 770. Limestone. Yaxchilan, Chiapas, Mexico. British Museum. London, England, United Kingdom.