Welcome to Sacsayhuaman, one of the most awe-inspiring archaeological feats on the planet. You are currently standing at approximately three thousand seven hundred and one meters above sea level, overlooking the historic capital of the Inca Empire, Cusco. As you look out over the valley, try to imagine the city below in the shape of a puma. In the fifteenth century, the great Inca ruler Pachacuti designed Cusco with this sacred animal in mind; the city streets formed the body, and this massive citadel where you stand today served as the head. While often called a fortress, experts believe this site was primarily a religious sanctuary and a Sun House for the ruling dynasty. Take a deep breath and feel the thin, crisp Andean air as we begin our journey through centuries of history and stone.