There's no more striking introduction to Extremadura than the Puerto de Tornavacas—literally, the "point where the cows turn back." Part of the N110 road northeast of Plasencia, the pass marks the border between Extremadura and the stark plateau of Castile. At 1,275 meters (4,183 feet) above sea level, it has a breathtaking view of the valley formed by the fast-flowing Jerte River. The valley's lower slopes are covered with a dense mantle of ash, chestnut, and cherry trees, whose richness contrasts with the granite cliffs of Castile's Sierra de Gredos. Cherries are the principal crop. To catch their brilliant blossoms, visit in spring. Camping is popular in this region, and even the most experienced hikers can find some challenging trails.