According to Travel + Leisure, the Monasterio Hotel at Cusco is in the top 5 best hotel service list of Latin America.

http://www.travelandleisure.com/arti...s-best-service

Built in 1595, on the former site of an Inca palace, this magnificent baroque-style monastery is one of the most beautiful examples of restoration in the country. Its ancient architecture has been restored maintaining the nobility and import of its courtyards and chambers, while respecting the simplicity of detail. Its refurbishing has been done with meticulous care, making the conversion to a hotel imperceptible.
http://www.monasteriohotel.com/web/o...monasterio.jsp

I just read Casitas del Colca at Colca Canyon Arequipa is within the most popular hotels for rest/spa in South America.
http://www.lascasitasdelcolca.com/galeria.html