Take a stroll through the town. There are still several houses dating back from Incan time.
Ruins of Ollantaytambo - ruins of largely religious significance, they doubled as the the last and largest defensive structures near the plains below where the Incas defeated the Spaniards in battle. Admission with boleto turistico (can be purchased at entrance to ruins) or 130 soles for just this site, 70 soles for students. Local guides can be hired in the market area below the ruins (20 soles). Or, do it yourself by purchasing the book most of the guides use, ¨Cuzco and the sacred valley of the Incas¨(salazar and salazar) which has an extensive section on Ollantaytambo. The book can be purchased in the market below the ruins (50 soles) or in advance in Cuzco (35 soles). Neither the guides nor the guidebook discuss the battles, for information on this research on your own in advance. Tours focus largely on the unique architectural significance of the sun's rays on the cad face of the canyon wall and on the temple walls, the still functioning fountains, and the large stone operating table. Even if you're not an archeology buff or ruins fan, these are worth seeing. Beautiful views abound.
Pinkullyuna is the hill with Incan storehouses overlooking the town and facing the main ruins. To get to the path up to these ruins, follow the road closest to the base of the hill (the rightmost one in the town grid when facing Pinkullyuna). You will see a small sign with an arrow pointing to a steep path, which takes you up to a series of ruins and storehouses. Admission is free, and from here you can see some of the most spectacular views of the Ollantaytambo ruins and town and the Urubamba Valley. It's a lovely hike, and can be done in just an hour or two. Some parts of the various path can be a little harrowing, especially the less oft used side paths (all of these also lead to ruins that are less apparent). Go with a friend or at least make sure you let your hosts at the hostel know where you have gone in case something should happen.