These settlements are by no means limited to Switzerland. They stretch in a long zone along the Alps from Savoy and southern Germany through Switzerland into Austria.[50] Herodotus mentions them in the Balkan Peninsula. The amount of bronze seems to increase as we pass from east to west. They are found frequently in the Italian lakes, mostly containing relics of the Bronze Age, though here the western settlements contain little or no metal. A second series has been discovered in Britain and northern Germany, and extending into Russia. These are considerably younger. The scheme of the lake-dwelling was used in historic times in Ravenna and Venice. Large numbers are still inhabited in the far east. A sunny, sheltered shore, protected by hills from storms and action of waves, was always an attractive site.[51] The character of the land, if open and suitable for pasturage and cultivation, was doubtless important. Much depended on the character of the bottom. Where the shore shelved off gradually and was composed of marl or sand, the piles could be easily driven, and could hold their place firmly. Even if the shore was somewhat too hard and the piles could be driven only a little distance, they were strengthened by piles of stones, often brought from a considerable distance. When a suitable location had been discovered and selected the trees were felled partly by the use of stone axes, and partly by fire, and one end of the log was pointed by the same means, according to Avebury. Their diameter was from three to nine inches, and their length from fifteen to thirty feet. During the Bronze period larger trees were felled and split, and larger piles had to be used in the deeper water farther from the shore.[52] These rudely sharpened piles were driven into the bottom by the use of heavy stone mallets. This must have involved an immense amount of hard labor, for at the settlement of Wangen 50,000 piles were used, though not all probably at the same time. Messikommer calculated that at Robenhausen over 100,000 were used. We find sometimes a different foundation. It consists of a solid mass of mud and stones, with erect and also horizontal logs binding the whole structure firmly together. This is evidently a ruder, simpler, and perhaps more primitive, mode of building. It was less suited to an open situation, exposed to heavy waves, and seems to occur more often in smaller lakes now often filled with peat.[53] Wauwyl and Nieberwyl are good illustrations of such a "_Packwerkbau_." Some have considered them as originally floating rafts.