This region of Chile is a temperate rainforest, much like the Pacific Northwest of the US. There are hundreds of azure glacial lakes scattered amongst the mountains. Small towns in the high alpine valleys are reminiscent of the Alps.
A good place to start is from Ensenda. Cruise the slopes of Osorno in Vicente Perez Rosales Park and descend to Petrohue Falls. After a day of mountain mountain biking in Puyehue National Park near Las Cascades, soak in the nearby hot springs. Next, tackle the wildlife refuge at the foot of Casablanca Volcano. Bike along the lake near Pucon, which is one of the most popular destinations.
Overall, Northern Patagonia is the 1st most popular mountain bike trail of all 4 mountain biking rides in Chile.