Puka Pukara is an interesting site for tourists to visit. It is a military archaeological site located very near to Cusco. Better known as the Red Fort due to the calcareous stones rich of iron with which it was built. At dusk the color of the rocks are reddish. Experts say the fortress functioned as Protection of Tambomachay, an important palace in Inca times. Also it was used to defend Cusco and the Inca Empire in general. The fort is made of walls, terraces, staircases and passages and therefor it is believed that Tambomachay was an administrative center. It is also assumed that it might have functioned as an hostel offering rest and food for travelers on their way to Huchuy Qosgo and Calca in the Sacred Valley. The location is open for tourists throughout the year. There, travelers can admire the interior squares, baths, aqueducts, watchtowers and an easily recognizable Inca Trail.