All the main towns in Castile–León and Castile–La Mancha are accessible by multiple daily trains from Madrid, with tickets running about €10–€30, depending on train speed (the high-speed AVE service costs more), the time of day, and the day of the week. Several towns make feasible day trips: there are commuter trains from Madrid to Segovia (30 minutes), Guadalajara (30 minutes), and Toledo (30 minutes). Trains to Toledo depart from Madrid's Atocha station; trains to Salamanca, Burgos, and León depart from Chamartín; and both stations serve Ávila, Segovia, El Escorial, and Sigüenza, though Chamartín may have more frequent service. Trains from Segovia go only to Madrid, but you can change at Villalba for Ávila and Salamanca.
For Extremadura, trains from Madrid stop at Monfragüe, Plasencia, Cáceres, Mérida, Zafra, and Badajoz, running as often as six times daily. The journey from Madrid to Cáceres takes about four hours. Within the province there are services from Badajoz to Cáceres (3 daily, 1 hour 55 minutes), to Mérida (5 daily, 40 minutes), and to Plasencia (2 daily, 2 hours 40 minutes); from Cáceres to Badajoz (3 daily, 1 hour 55 minutes), to Mérida (5 daily, 1 hour), to Plasencia (4 daily, 1 hour 10 minutes), and to Zafra (2 daily, 2 hours 10 minutes); from Plasencia to Badajoz (2 daily, 3 hours), to Cáceres (4 daily, 1 hour 10 minutes), and to Mérida (4 daily, 2 hours 10 minutes). Note that several cities have separate train stations for normal versus AVE high-speed rail service; the newer AVE stations are often farther from town centers.
RENFE. 90/232--0320; www.renfe.com.