Peter Frost is a writer, photographer, archaeologist, and independent scholar who has explored the Andes and Amazon for 35 years, and lived in Peru since 1987. He has published four books on Peru and Ecuador, including a guide to the Cusco region and a book on Machu Picchu. In 2001 and 2002 he led National Geographic Society-sponsored expeditions into the remote region of Vilcabamba, finding and exploring the previously unknown Inca and pre-Inca site of Qoriwayrachina (National Geographic magazine, March 2004).