Landlocked Aragón, along with Navarre, forms the northeastern quadrant of Spain. It is an ancient land composed of three provinces: Zaragoza; remote Teruel, which is farther south; and Huesca, in the north as you move toward the Pyrenees. These are also the names of the provinces' three major cities.
Most of Aragón constitutes terra incognita for the average tourist -- which is unfortunate, since it is one of the most history-rich regions of the country. You can visit it as an extension of your trip to Castile to the west, or as a segment of your trek through Catalonia to the east. Huesca, close to the mountains, is ideal for a summer visit -- unlike most of Aragón, especially the fiercely hot southern section, which has Spain's worst climate. Winter is often bitterly cold, but spring and autumn are ideal.
Aragón is known best for two former residents: Catherine of Aragón, who foolishly married Henry VIII of England; and Catherine's father, Ferdinand of Aragón, whose marriage to Isabella, queen of Castile and León in the 15th century, led to the unification of Spain.
Aragón also prides itself on its exceptional Mudéjar architecture and on its bullfighting tradition. In September many villages in the region have their own festivals, when bulls run through the streets. What they don't have is the good promotion that Hemingway gave the festival at Pamplona, in the neighboring province of Navarre. On the other hand, they aren't plagued with wine-drunk tourists -- the curse of the Pamplona festival. In folklore, Aragón is known for the jota, a bounding, leaping dance performed by men and women since at least the 1700s.
Aragón's capital, Zaragoza, is the most visited destination in the region because it lies on the main route between Madrid and Barcelona. If you're driving from Madrid to Barcelona (or vice versa), make a detour to Zaragoza. If Aragón interests you while there, stick around to explore this ancient land.