The many features of this sprawling site take a while to explore. Archaeology fans will not be content with the half-day allotted by a four-day trek.
Take special care exploring these ruins as the site's popularity can cause a huge impact on the infrastructure and there is little funding for its conservation.
Trail guides don't always offer detailed information. It's well worth bringing a copy of Machu Picchu's Sacred Sisters: Choquequirao & Llactapata by Gary Ziegler. Peter Frost's Exploring Cusco is also useful.