elpais– 1Valley of Ultzama (Navarre) One of the highlights of Bosque de Orgi (Forest of Orgi), located in Lizaso, in the Spanish region of Navarre, is an oak forest containing specimens that are hundreds of years old. The area has well-marked trails going through and around it. The valleys of Ultzama and Basaburua also feature other good spots for enjoying the colors of the fall season. One of them is a simple walking trail that starts in the municipality of Jauntsarats, meanders through the oak forest of Beheitiko and takes visitors to the foot of two very singular specimens with Monumental Tree designation: the oak tree of Beheitikolanda, which is 30 meters tall, and the oak tree of Kisulabe, whose trunk is believed to be the widest in the entire region of Navarre. To the north of Ultzama, on the border with the neighboring valley of Baztan, the area near the port of Belate still conserves valuable forests of ancient beech, oak and chestnut that form a special habitat that is part of Red Natura 2000, a network of nature protection areas in the European Union. For more information: bosquedeorgi.com and espaciosnaturales.navarra.es

2Selva de Oza (Huesca) This dense forest in the natural park of Valles Occidentales, in the portion of the Pyrenees that falls within the limits of the Spanish region of Aragón, reaches a climax of color when its fir, pine and beech combine in an explosion of greens, yellows and ochres. The peaks here reach as high as 3,000 meters, and the valley of Hecho affords numerous hiking options for beginners and pros alike on either side of the Aragón Subordán river. One trail leads to the Corona de los Muertos (Crown of the Dead), believed to be a burial site from the Neolithic period, around 3,000 BC. Another trail leads hikers to the beautiful adjacent valley of Estriviella, while a third takes them up to the castle of Acher, at an elevation of 2,384 meters, which affords a broad view of the Selva de Oza forest. There is a campsite (camping-selvadeoza.com) that will remain open during the upcoming long weekend of October 12, after which it will close for the season. For more information: selvaoza.es GETTY IMAGES

3Castañar de El Tiemblo (Ávila) Alder, oak, mountain elm, hazelnut, maritime pine and chestnut all feature prominently in the Castañar de El Tiemblo (Chestnut grove of El Tiemblo), in the natural reserve of the valley of Las Iruelas, in Spain’s Ávila province. The oldest oak has been dubbed El Abuelo (The Grandfather) and is estimated to be over 500 years old. A low-difficulty circular trail (PR-AV54) begins at the recreational area of El Regajo and runs for 4.3 kilometers, passing close to this spectacular specimen and winding its way through the enormous chestnut trees of El Resecadal. For more information: patrimonionatural.org

4Valle del Genal (Málaga) In Sierra de las Nieves, a natural enclave in southwest Málaga that became Spain’s 16th national park this past summer, it is important to listen as much as it is to look if you go there in the fall. At sunset, visitors can not only enjoy the palette of greens, yellows and browns from the forests of holm oak, cork oak, pine, fir and chestnut, but also hear the bellowing calls of male deer during the rut. The area known as Bosque de Cobre (Copper Forest), which gets its name from the reddish tinge on the leaves of the chestnut trees that cover the mountain range and the neighboring Valley of Genal, contains several well-marked trails. For more information: sierradelasnieves.es and malaga.es

Fragas do Mandeo (A Coruña) The ‘fragas’ of Galicia are probably the closest thing in real life to an enchanted forest. They are dense, humid. old-growth forests whose tall, imposing trees seem to dare visitors to step within. One of the most pristine of these areas is the Fraga do Mandeo, near the town of Betanzos and part of the biosphere reserve Mariñas Coruñesas e Terras do Mandeo. Here, both banks of the Mandeo river are covered with ‘carballos’ (a local name for the common oak), ash, chestnut, alder, elm and maple, along with underbrush species such as the endangered ‘píjara,’ a fern from the Tertiary period. There are two trails leading out from the Chelo nature learning center. The shorter and easier one (2.5 km round-trip) goes to Teixeiro Bridge after winding through a forest of hazelnut and the ruins of an old water mill. The second trail (6.3 km) follows the Mandeo upriver, taking hikers past the Cabra reservoir (home to salmon) and the abandoned spa of O Bocelo, whose springs continue to spout sulfur water. The lookout point of Espenuca offers excellent views of Mandeo canyon and the area of As Mariñas. For more information: fragasdomandeo.org and marinasbetanzos.gal

6Nansa River Path (Cantabria) A magnificent expanse of gallery forest runs along the lower end of the Nansa river, in Spain’s northern region of Cantabria. Hazelnut, chestnut, ash and alder add their own special colors to a 14-kilometer trail that begins in the village of Muñorrodero and presents very little difficulty, as steps have been built to clear the steepest spots. The entire trail is contained within the Nansa River Special Conservation Zone, which is part of the EU’s Red Natura 2000. For those unwilling to walk the whole distance, the halfway point is approximately located at the hydroelectricity plant of Trascudia. Animals that are often spotted in the area include grey herons, common kingfishers and otters. A visitor center in San Vicente de la Barquera offers guided tours and activities in the area. For more information: redcantabrarural.com

7Torca de los Melojos (Albacete) Among the foothills of the mountain ranges of Alcaraz and Segura, in southwest Albacete, the autumn charms of the natural park of Los Calares del Mundo y de la Sima go well beyond the famous river source known as Chorros del río Mundo. There are the colors of the gallery forests running along other rivers in the area, including the Segura, Zumeta, Taibilla and Bogarra. And there is the remote forest of Torca de los Melojos, which is accessible from the starting point of Fuente de las Raigadas, in Riópar. The trail is between seven and eight kilometers in total, and cuts through pine, holly, maple, kermes oak and yew. Inside the ‘torca,’ which is a circular depression in the land with steep sides, there is a singular oak grove with ancient specimens that manage to survive because of the high humidity content. For more information: areasprotegidas.castillalamancha.es and turismosierradelsegura.es

8Fageda del Retaule (Tarragona) In the landscape of pine, holm oak and mountain ridges of the natural park of Els Ports, in Catalonia’s Terres de l’Ebre (in southwest Tarragona province), there are also clutches of deciduous trees, including the unique Fageda del Retaule, said to be Europe’s southernmost forest of beech. This collection of tall, centuries-old trees sits on the humid northern face of the gorge of Retaule. One of the most notable specimens is a tree called Faig Pare (Father Beech, in the Catalan language), which was declared a Monumental Tree in 1992 and is estimated to be 250 years old. Its trunk has perimeter of four meters, and its visible roots make it a favorite spot for pictures. For more information: terresdelebre.travel