Chinchero is one of the few towns in the region that is higher than Cusco (it's located at 12,500 feet) and so make sure you are acclimated before walking around.
The ruins at Chinchero consist of a series of nested terraces rising up to a plateau upon which sits a church built in the early 1600's.
There are several hikes that can be done from Chinchero. If you walk through the ruins, down into the valley, and follow the path along a riverbed, you will eventually emerge, after a few hours, at a small town (name forgotten) where there are frequent combis to Urubamba. The path goes along the side of a verdant steep-sided valley offering beautiful views.