Wander the Plaza de Armas, Cusco's central colonial square—a busy hub day and night and a fine place to watch daily life. The cathedral, completed in 1654, is a UNESCO World Heritage contribution to the city; inside, look for the 1753 Marcos Zapata painting of the Last Supper featuring a regional detail that makes it unmistakably Peruvian.
The Church of the Society of Jesus is another highlight, with ornate Spanish Baroque design. Walk uphill to San Blas for sunset views, small bars, and independent shops.