Yet these military works, which exhausted the public treasure, could not remove the just apprehensions of Justinian and his European subjects. The warm baths of Anchialus in Thrace were rendered as safe as they were salutary; but the rich pastures of Thessalonica were foraged by the Scythian cavalry; the delicious vale of Tempe, three hundred miles from the Danube, was continually alarmed by the sound of war; and no unfortified spot, however distant or solitary, could securely enjoy the blessings of peace. The straits of Thermopylæ which seemed to protect, but which had so often betrayed, the safety of Greece, were diligently strengthened by the labours of Justinian. From the edge of the seashore, through the forest and valleys, and as far as the summit of the Thessalian Mountains, a strong wall was continued, which occupied every practicable entrance. Instead of a hasty crowd of peasants, a garrison of two thousand soldiers was stationed along the rampart; granaries of corn and reservoirs of water were provided for their use; and by a precaution that inspired the cowardice which it foresaw, convenient fortresses were erected for their retreat. The walls of Corinth, overthrown by an earthquake, and the mouldering bulwarks of Athens and Platæa, were carefully restored; the barbarians were discouraged by the prospect of successive and painful sieges; and the naked cities of Peloponnesus were covered by the fortifications of the Isthmus of Corinth. At the extremity of Europe, another peninsula, the Thracian Chersonesus, runs three days’ journey into the sea, to form, with the adjacent shores of Asia, the straits of the Hellespont. The intervals between eleven populous towns were filled by lofty woods, fair pastures, and arable lands; and the isthmus, of thirty-seven stadia or furlongs, had been fortified by a Spartan general nine hundred years before the reign of Justinian. In an age of freedom and valour, the slightest rampart may prevent a surprise; and Procopius appears insensible of the superiority of ancient times, while he praises the solid construction and double parapet of a wall whose long arms stretched on either side into the sea, but whose strength was deemed insufficient to guard the Chersonesus, if each city, and particularly Gallipoli and Sestos, had not been secured by their peculiar fortifications.