Old Castile is bordered on the N. by the Bay of Biscay, on the E. and N.E. by Biscay, Alava, Navarre, and Aragon, on the S. by New Castile, and on the W. by Leon and Asturias. It is divided into the provinces of Burgos, Logroño, Santander, Soria, Segovia, Avila, Palencia, Valladolid, and has an area of 25,409 square miles, and a population estimated in 1870 at 1,689,864 inhabitants. The country consists of vast plains, which form, between the Cantabrian chain in the north and the chain of Sierras stretching south-west from Aragon to Estremadura, a great table-land, of a height between 2500 and 4000 feet above the sea. The principal rivers are the Douro and the Ebro. The plains are barren and dry, with scarcely a tree, meadow, or spring of water; but the hills bordering the mountain ranges are well clothed with oak-forests. The climate is healthy, but subject to great extremes of cold and heat; frosts in the higher regions may last three months at a time. The soil is productive, but poorly cultivated; the harvests of wheat, however, are abundant. Wine and oil of inferior quality, and madder, are produced in considerable quantity, but fruits are scarce except at Bureba. The export trade is chiefly in wool, cattle, sheep, and wheat. The bad state of the roads (which are often impassable for mules), the insufficiency of railway communication, and the neglected condition of the Port of Santander, are great obstacles to commerce.

New Castile is bounded on the N. by Old Castile, on the E. by Aragon and Valencia, on the S. by La Mancha, on the W. by Estremadura. It forms the southern portion of the great central table-land of Spain, and comprises the provinces of Madrid, Toledo, Guadalajara, and Cuenca. The total area is 20,178 square miles, inhabited by a population estimated in 1870 at 1,277,123. The principal mountain ranges are the Sierra Guadarama in the north, and the Sierra Morena in the south. The chief rivers are the Tagus, Guadiana, Guadalquiver, Segura, and Xucar. The climate is more rigorous than that of Old Castile, and the mean temperature, on account of the elevation of surface, is not more than 59°; but the heat in summer is extreme in the valleys. The rainfall is not more then 10 inches in a year; the winds are dry and violent. The whole country presents the aspect of a barren dusty steppe, with patches of olive-trees here and there, and wheat, pea, and saffron fields. During the rainy season the vegetation is very luxuriant; but agriculture is in a backward state; the soil is fertile, but the rivers are not used for its irrigation. The total quantity of wheat raised is barely sufficient for the wants of the population. Hemp and flax and olive-trees are cultivated. Timber and fire-wood are becoming dearer, as the country is very little wooded. Honey is gathered in considerable quantities; and sheep, oxen, and mules are reared in great numbers. Iron, salt, and quicksilver are worked; the mineral resources are good, but ill developed. The manufactures are chiefly of woollen goods, plain and figured velvets, silks, satins, calicoes, stockings, earthenware, and cutlery.

The inhabitants of both Old and New Castile are a loyal and manly race, preserving the primitive simplicity and pure Spanish, as well as the pride, of their forefathers. They are uneducated and inclined to bigotry, but naturally shrewd and intelligent. The tillage of the land and the pasturing of sheep are their chief employments.