The most popular way to visit Ollantaytambo is with a tour agency on a day trip from Cusco. Usually tour operators combine a stop in Ollantaytambo with several other surrounding villages like Chinchero or Piscac, and prices start at what is a called "bargain" $10. The most economic, and arguably the most enjoyable, way to explore Ollantaytambo is at your own leisure and on your own time by going it alone without a guided tour.
Bus
Though rumors abound of buses running directly between Cusco and Ollantaytambo, the easiest thing to do is to catch a bus from Cusco to Urubamba from one of two Cusco stations that service Urubamba, and then to change buses. The terminal on Grau runs via Chinchero (1.5 hours) while the terminal on Avenida Tullumayo takes the Pisac route (2 hours). Fares to Urubamba are $1-$1.50. Once at the Urubamba bus terminal, there's no shortage of collectivos running to Ollantaytambo or any question about where to find them. Collectivo operators bound for Ollantaytambo greet passengers from Cusco the moment they step off the bus and usher them into a waiting mini-van. From Urubamba, the ride into Ollantaytambo takes about 30 minutes in a collectivo ($0.30) or, for those with deep pockets, taxis make the trip slightly quicker for about $3.
Train
Ollantaytambo is the mid-point for trains running between Cusco and Aguas Calientes (the point of disembarkation for Machu Picchu and the last stop on the train). Though it's tempting to stop in Ollantaytambo en route or returning from Aguas Calientes, it can be an expensive endeavor if done solely by train, as fares to and from Ollantaytambo to Aguas Calientes are the same as from Cusco. Keep in mind that while it's possible to get to Ollantaytambo by road, Aguas Calientes can only be reached by train, and therefore travel between Aguas Calientes and Ollantaytambo requires train travel. The rail station in Ollantaytambo is about 1200 meters from the town proper, and the road is currently under serious construction, so be prepared to walk most of the distance.
Nine trains, offering a variety of classes and rates, stop in Ollantaytambo from Cusco every morning before continuing on to Aguas Calientes. It's possible to disembark in Ollantaytambo from a morning train, as well as embark on any of the trains en route to Aguas Calientes. Though a number of trains return to Cusco from Aguas Calientes everyday, only three trains returning to Cusco stop in Ollantaytambo, so be sure to correctly book your ticket if you plan to alight at Ollantaytambo from Aguas Calientes. Trains leave Ollantaytambo bound for Cusco everyday between 5 p.m. and 6:45 p.m. Schedules and exact times are subject to change, so check with the train station directly or visit www.perurail.com for information.