Man has always been intrigued by the grandeur of mountains. If you are drawn to high peaks and awesome vistas, a climb up Sierra de Guara should be on your itinerary.
You'll be spoiled for sightseeing choice when in Casbas de Huesca. Sierra de Guara is a great place to start here, but there are lots of other fine attractions to explore. Ermita de San Miguel, Ermita de San Chinés, and Ermita de Nuestra Señora de Sescún are near the steep landmass and will fill in your day nicely.