Cerro Castillo National Reserve, in the Aysén region along the Carretera Austral, offers mountain scenery comparable to Torres del Paine, but with a fraction of the visitors, making it an increasingly popular alternative for travelers who've already done the classic Patagonian circuit.
The main trek
The trail to the Cerro Castillo Lagoon lookout is the reserve's most popular hike: a full day round trip (7 to 9 hours) up to a viewpoint overlooking the granite spire that gives the mountain its name and a turquoise glacial lagoon.
The multi-day trek
For those with more time, a 4-day trek crosses the reserve end to end, far less traveled than the W circuit in Torres del Paine and requiring more self-sufficiency, since the refuge infrastructure is more limited. Being right on the Carretera Austral, it combines easily with other stops on a road trip along the route.
