Pasarelas de Alquézar
Take a breathtaking riverside hike (1½ hours) on the Ruta de las Pasarelas loop, which hugs near-sheer cliffs that plunge into rushing turquoise waters. There's a waterfall, a cave, and plenty of placards with information on the surrounding nature and historical buildings. Be sure to bring plenty of water and to arrive early, since parking (follow the signs) is limited. Certain stretches are on metal pathways with steep drops, so those with limited mobility or a fear of heights should skip this one. The trail starts at Plaza de Rafael Ayerbe beside the ayuntamiento (town hall). No bikes or pets are allowed.