As Alice in Wonderland discovered, cave entrances, tunnels, spirals and mirrors can transport people to strange worlds where anything is possible. Portals investigates how we move beyond the conscious and physical world using our senses, into other realities of the spiritual and the divine. Portals looks at the techniques used to alter consciousness practised by shamans, monks and other religious specialists. These include the use of drugs, as well as drumming, chanting and meditation. The book provides a new, anthropologically-grounded perspective on the wide-ranging questions about the realities of human consciousness and mystical, spiritual and religious experience.