The White Drini Spring is one of the easiest nature excursions from Peja, a clear karst spring and waterfall set below the mountains east of the Rugova approaches. It is not wilderness, but the water, cliffs, and short paths make it a satisfying break from the town.
Go for the spring itself rather than expecting a long hike. The area is popular with local visitors, especially in warm weather, and works well as a short stop before or after the Patriarchate of Peć and Rugova Gorge.