Nearly 8,000 feet high in the Andes, Machu Pichu is an extraordinary site. Dating most likely from the mid 15th century, it was abandoned a century later and only “rediscovered” in the early 20th century. Walking among its structures you have to appreciate the skill of the inca stone masons. And from just about any viewpoint, the integration with the mountaintop site is breathtaking. Similarly, Ollaytantambo (Sacred Valley) and Sacsayhuaman (Cusco) are marvelous examples of Inca stone work.