Cusco was the capital of the Incan Empire and this importance is reflected in the region’s impressive archaeological sites.
North of the city are four main sites, entry to which is included in the main Boleto Turistico del Cusco (Tourist Ticket): Tambomachay, Pukapukara, Qenqo and Saqsayhuaman. Along with smaller ruins, they make a great day hike. I enjoyed exploring the area enough to require two days.
The best way to see the sites is to take a taxi, bus or collectivo up to the furthermost site, Tambomachay, and then hike downhill back to Cusco via the other ruins.
Tambomachay includes terraced rocks and water features, the historical function of which is uncertain