Nova Scotia comprises the peninsula of Nova Scotia, connected to the mainland by a narrow isthmus, and Cape Breton Island in the northern part of the province, linked by the world's deepest causeway, which is 1.6km (1 mile) long. The Atlantic batters the eastern shore. The Bay of Fundy separates the southern part of the peninsula from the mainland, with the Northumberland Strait to the north. The northeast is rural and rocky, while the south and southwest are lush and fertile. The Fundy region's red soil was originally part of the present North African continent. Much of the province is covered by rivers. The land rises to 532m (1,745ft) on the northeast islands.