Note 722 — Chapter XI · —The Anthropo-Geography Of Rivers

The protection of an island location is almost equalled in the peninsulas formed by the serpentines or meanders of a river. Hence these are choice sites for fortress or settlement in primitive communities, where hostilities are always imminent and rivers the sole means of communication. The defensive works of the mound-builders in great numbers occupied such river peninsulas. The neck of the loop was fortified by a single or double line of ditch and earthen wall, constructed from bank to bank of the encircling stream.722 This was exactly the location of Vesontio, now Besançon, once the ancient stronghold of the Sequani in eastern Gaul. It was situated in a loop of the Dubis, so nearly a circle that its course seems to have been "described by a compass," Cæsar says, while fortifications across the isthmus made the position of the town almost impregnable.723 Verona, lying at the exit of the great martial highway of the Brenner Pass, occupies just such a loop of the Adige, as does Capua on the Volturno, and Berne on the Aare. Shrewsbury, in the Middle Ages an important military point for the preservation of order on the marches of Wales, is almost encircled by the River Severn, while a castle on the neck of the peninsula completes the defense on the land side.724 Graaf Reinett, at one time an exposed frontier settlement of the Dutch in Cape Colony, had a natural moat around it in the Sunday River, which here describes three-fourths of a circle.