Examples of head-scratchingly impressive building material can be found throughout the ancient world, and Maya lime plaster ranks high among them.
Scientists from the University of Granada in Spain explored why this plaster was a step above the building materials of its mesoamerican peers.
The secret ingredient was sap from nearby trees, introduced during the plaster-making process. The sap created insoluble crystalline structures (similar to those found on the shells of mollusks) that were well-suited to surviving the hot and humid climate of central America.
Full article https://www.popularmechanics.com/science/archaeology/a43658939/mystery-of-stronger-maya-plaster-solved/