This paper discusses archaeological, historical, and contemporary ethnographic evidence for the use of the San Pedro cactus in northern Peru as a vehicle for traveling between worlds and for imparting the ‘‘vista’’ (magical sight) necessary for shamanic healers to divine the cause of their patients’ ailments. Using iconographic, ethnohistorical, and ethnographic evidence for the uninterrupted use of this sacred plant as a means of access to the Divine and as a tool for healing, it describes the relationship between San Pedro, ancestor worship, water/ fertility cults and also the common symbolic associations between San Pedro and wind-spirits. It closes by suggesting that the more than 2000 year time-depth of using this plant as a means for accessing the realms of Spirit and as a tool for healing should serve to challenge the unfortunate tendency in the contemporary United States to consider this plant as a ‘‘recreational drug.’’ keywords: San Pedro cactus, Peru, shamanism, ancestor worship, cosmology, ecology