The Denver Ashtanga Center is located at 32nd and Jewell (it's right behind Three Dogs Tavern). They have both hour ($7)and 1.5 hr classes. They have all kinds of class packages or blocks of classes you want to buy in advance.
Cool place, small classes, and classes of all levels. The cool part for me was even if I could not do the entire strech or pose... I was always doing a portion. Just like in kayaking people take it do different levels, the beginner level was perfect for me. Ejoy.