Heart of the Serpent
From WikiRaider
The Heart of the Serpent is an Artifact in Shadow of the Tomb Raider. It is part of the Exodus collection. It can be found in Cozumel.
This mural depicts some kind of voyage or pilgrimage undertaken by the Maya. Seems they carried an item of great import, and traveled South, to the source of the pink fish.
The Amazon River, just like Jonah said.
Artefact description in the game inventory
Discovering this mural raises the Language Proficiency in the Ancient Maya Dialect Mam.
