Spain owes much to Castile, Aragón, and León, since these three kingdoms helped unify the various regions of the country. Modern Spain was conceived when Isabella of Castile married Ferdinand of Aragón in 1469. Five years later she was proclaimed queen of Castile and León. The Moors were eventually driven out of Granada, Spain was conquered, and Columbus sailed to America -- all during the reign of these two Catholic monarchs.

This proud but controversial queen and her unscrupulous husband fashioned an empire whose influence extended throughout Spain, Europe, and the New World. The power once held by Old Castile shifted long ago to Madrid, but there remain many reminders of its storied past.

In the ancient kingdom of León, which was eventually annexed to Castile, you'll find Salamanca, Zamora, and the provincial capital of León. Today the region is known for its many castles.

In Old Castile, we cover the inland provincial capital of Valladolid, where Isabella married Ferdinand and where a brokenhearted Christopher Columbus died on May 19, 1506. From here we move on to Burgos, once the capital of Old Castile. Vivar, a small town nearby, produced Spain's greatest national hero, El Cid, who conquered the Moorish kingdom of Valencia.