In summer the tourist offices of Segovia, Toledo, and Sigüenza organize Trenes Turísticos (miniature tourist trains) that glide past all the major sights; contact local tourist offices for schedules.
A great way to really get to know Extremadura is by bike (in any season but scorching summer), and you can essentially forego all maps by following the ancient Roman road, the Vía de la Plata. It runs through Extremadura from north to south along the A66 and passes by Plasencia, Cáceres, Mérida, and Zafra. Note that the region north of the province of Cáceres, including the Jerte Valley, La Vera, and the area surrounding Guadalupe, is mountainous and uneven: be prepared for a bumpy and exhausting ride. The regional government has also opened four Vías Verdes, or "green way" paths geared toward hiking and biking, along disused railroads; a notable (if rugged) one goes from Logrosán (a couple of miles southwest of Guadalupe) to Villanueva de la Serena (east of Mérida and near Don Benito). Check www.viasverdes.com for maps of this and other trails.
Equiberia. Horseback tours, ranging 1–10 days, offer a unique way to experience the gorges, fields, and forests of the Sierra de Guadarrama, Segovia, Ávila, and beyond. Navarredonda de Gredos, Ávila, Castille and León, 05635. 68/934--3974; www.equiberia.com. From €150.
Hidden Trails. Based in Vancouver, Canada, this company offers weeklong horseback tours of the Gredo Mountains on the border of Cáceres province. Prices include accommodations and meals. 888/987–2457; 604/323–1141; www.hiddentrails.com. From €950.
Valle Aventura. Hiking, horseback riding, cycling, and kayaking trips in the Jerte Valley can be organized with this company. Prices may not include meals. 63/663--1182; www.valleaventura.com. From €180.