The Southern Carpathians offer the highest peaks at Moldoveanu Peak (2,544 metres) and Negoiu (2,535 meters) and more than 150 glacial lakes. They have large grassland areas and some woodlands but few large depressions and subsoil resources. The region was crisscrossed by an ancient network of trans-Carpathian roads, and vestiges of the old Roman Way are still visible. Numerous passes and the valleys of the Olt, Jiu, and Danube rivers provide routes for roads and railways through the mountains.