district and borough, administrative county of East Sussex, historic county of Sussex, England, on the English Channel coast. It lies at the eastern end of the chalk South Downs, which reach the sea in high cliffs at Beachy Head (534 feet 【163 m】). The modern resort town of Eastbourne dates from the early 19th century and the coming of the railway. The town's development—in a spacious, regular layout—took place on the estates of the duke of Devonshire and others. The Wish Tower and the Redoubt are defenses dating from the Napoleonic threat of invasion. Eastbourne also has grown as an attractive residential town, as well as a resort and conference centre. Area 18 square miles (46 square km). Pop. (2001) 106,562.