Yes, provided that you are suitably acclimatized to the altitude prior to starting the trek. Ollantaytambo is at a much lower altitude than Cusco and time spent there (or anywhere else in the Sacred Valley) doesnt count towards your acclimatization period. We recommend that you spend at least 2 nights in Cusco, preferably three, prior to spending the night at Ollantaytambo. When you come to our office you must also give us the name of your hotel in Ollantaytambo so that we can arrange a time to pick you up. The hotel would need to be accessible for the bus, otherwise you would need to meet us in the main plaza. If you do not have a hotel reservation and you decide to meet us in the main Plaza in Ollantaytambo at a pre-arranged time we cannot accept responsibility if we cant find you and leave you behind!! We do not pick up clients from any intermediate hotels between Cusco and Ollantaytambo.