The barren escarpments and forests of the Apennines form a charming contrast to the valleys and rounded hills of Lower Tuscany, where nearly every height is {240} surmounted by the ruins of a mediæval castle; graceful villas are scattered over the verdant slopes, farmhouses stand in the midst of vineyards and pointed cypresses, and every cultivable spot is made to yield a rich harvest. Historical associations, the taste of its inhabitants, the fertility of the soil, an abundance of running water, and the sweetness of the climate all combine in making Central Tuscany one of the most privileged regions of Italy. Protected by the rampart of the Apennines against cold northerly winds, this region faces the Tyrrhenian Sea, whence blow warm and humid winds of tropical origin. The rains they bring are not excessive, thanks to the screen formed by the mountains of Corsica and Sardinia, and the happy disposition of the detached hills near the coast. The climate of Tuscany is essentially temperate, and to its equability, no less than to the natural beauty of their abode, the Tuscans owe, no doubt, much of their gaiety, their good-nature, fine taste, poetical feeling, and facile imagination. [Illustration: Fig. 82.—THE GOLFOLINO OF THE ARNO, NEAR SIGNA.] The valley of the Arno completely separates the hills of Southern Tuscany, usually known as the “Sub-Apennines,” from the principal chain of the mountains. This valley, with its defiles and ancient lake basins, may be likened to a moat {241} bounding the wall of the Apennines. The vale of Chiana, originally an arm of the sea, and then a lake, forms the uppermost portion of the zone which separates the Apennines from the hills of Southern Tuscany. Then follows the Campagna of Florence, an ancient lake basin, which it would be easy to flood again by building a dam across the defile of the Golfolina, through which the river makes its escape, and which was rent asunder by the “Egyptian Hercules.” Castruccio, the famous commander of the Luccans, actually proposed to flood the plains of Florence in the fourteenth century by constructing a dam across this defile; but happily his engineers pronounced the scheme to be impracticable, for they supposed the difference of level to amount to 288 feet, whilst in reality it is only fifty. [Illustration: Fig. 83.—DEFILES OF THE ARNO. From the Austrian Staff Map. Scale 1 : 285,000.]