About six kilometres south of Pescasseroli, the village of Opi sits on a rocky spur at over a thousand metres, its medieval houses stacked above the valley floor in the characteristic Apennine way that made the village look like a natural extension of the rock. The view from the road approaching it is one of the better photographs in the park. The village itself is tiny — a few hundred residents, a church, and lanes so steep and narrow that cars are essentially useless.
Opi is also the starting point for the Valle di Opi wildlife walk, one of the park's best routes for bear sightings: a 7-kilometre loop through open meadow and beech forest along the valley floor. The park authority runs guided dawn excursions from Opi in summer. Even without wildlife, the walk through the beech forest below the village is excellent.