Carved into the ridges of the Andes, deep in the Sacred Valley of Peru, Ollantaytambo is just one of the countless ancient treasures you'll pass as you make your way to the start of the bucket-list Incan Trail. It sits at nearly 2,800 meters above sea level, with a history that ranges back through the Spanish conquest of South America to the years of Incan imperial dominion over the mountains. As a complex, it is up there with Machu Picchu as one of the most important archaeological sites in the Cuzco region. Spreading out from the fast-flowing Patakancha River, it encompasses big plazas and marketplaces, half-ruined adobe dwellings and rough-stone cottages from the 15th century. The shrines of Cerro Bandolista are the piece de resistance of it all. Head there with an Ollantaytambo tour guide to delve into the mysterious Sun Temple and see the formidable Wall of the Six Monoliths peering across the Andes. Another highlight is the sheer-cut agricultural Terraces of Pumatallis. They represent an innovation of Incan engineering, cascading down the steep-sided Sacred Valley to create layers of different climactic zones where various crops could be grown. Modern Ollantaytambo also charms, awash with handsome colonial buildings and cacti-topped squares.