MEXICO: Cacao was an integral part of Maya life and was grown in well-guarded sacred groves. However, since much of the Yucatán’s hot, arid environment is unsuitable for cultivation of cacao trees, archaeologists have wondered how they grew so bountifully. Soil samples taken from several cenotes, or sinkholes, near Maya sites revealed the presence of caffeine and theobromine, biomarkers of cacao. The cenotes may have provided both humidity and shade, creating the perfect microclimate for the trees.