Fluctuations in water resources is one of the main factors modulating ecosystem dynamics, human population changes and culture in semiarid regions. One of the largest high-altitude semiarid regions of South America is the Altiplano in the Central Andes. With an elevation of 4.000 m this region has been the environment for the settlement of many communities who have inhabited the region for thousands of years. Tree-ring research has been developed in this region allowing the reconstruction of the dynamics of water resources during the last millennia. Besides, on the mountain tops of the Altiplano exists many high-altitude pre-Columbian sanctuaries which are framed within the remarkable relationship between mountains and water, which was a fundamental feature on which local cultures based their complex religious beliefs related to mountains as sources of fertility. The existence of archaeological wood on this sites utilized as offerings and/or firewood, and the possibility to develop regional tree-ring chronologies in the area allow the tree-ring dating and the development of precipitation reconstructions. Here we present a new precipitation reconstruction for the Andes of Atacama and the dating of three high-altitude sanctuaries located on mountain tops at 6,000 m asl utilizing tree-ring widths and 14C wiggle-matching of tree-ring sequences. For the last, we utilize a recently developed regional 14C curve from the Altiplano region. The dating and occupancy of these water-related sanctuaries will contribute to a better understanding of the relationship between humans’ religious beliefs and the semiarid environment that inhabited.