We went to Cusco for three days to acclimate to the altitude before continuing to Machu Picchu and the high Atacama. For us the best thing about Cusco -- which otherwise has quite a bit to offer -- was the Antigua Casona. What a gem! The restored hotel particulier oozes charm. The rooms are spacious and well-appointed (the vicuna rugs next to the bed are the softest thing our feet ever touched); the staff are attentive, friendly, and helpful (and speak excellent English); the restaurant and bar are excellent (breakfast was a treat every day); and the location -- up the hill from the buzzing main square in Cusco -- was perfect for exploring the town on foot. Keep in mind that you're over 12,000 feet, so the walk back up the hill to the hotel can be a real challenge the first couple of times, but it's worth it!