5.5 miles of steep wooden walkways along the bank of the Paiva River with scenic views. https://www.alltrails.com/trail/portugal/aveiro/passadicos-do-paiva-areinho-espiunca?u=i

Located in the beautiful Arouca Municipality of Aveiro, Portugal, the Passadiços do Paiva Trailhead (Areinho) is a stunning 8 km walk along a river and untouched landscapes. This hike is full of adventure for the nature lover, exploring biology, geology, and archaeology of the area. Along the route, hikers can spot an array of wildlife, gaze upon quartz crystals, and discover the waterfalls and river beach of Garganta do Paiva(G36), Cascata das Aguieiras (G35), Praia Fluvial do Vau (G30), Gola do Salto (G31), and Falha de Espiunca (G32). This hard difficulty trail is only open to individuals between sunrise and sunset, and safety is of utmost importance, so please wear appropriate clothing and shoes, stay on the trail, and follow all rules and regulations. Let the adventure of Passadiços do Paiva Trailhead (Areinho) begin!