Latvia lies on the eastern shores of the Baltic Sea on the level northwestern part of the rising East European platform. About 98% of the country lies under 200m elevation (640 ft.). The damp climate resembles New England's. With the exception of the coastal plains, the Ice Age divided Latvia into three main regions: the morainic Western and Eastern uplands and the Middle lowlands. Latvia holds over 12,000 rivers, only 17 of which are longer than 60 miles, and over 3,000 small lakes, most of which are eutrophic. Woodland, more than half of which is pine, covers 41% of the country. Other than peat, dolomite, and limestone, natural resources are scarce. Latvia holds 531km (329 mi.) of sandy coastline, and the ports of Liepaja and Ventspils provide important warm-water harbors for the Baltic littoral, although the Bay of Riga itself is rather polluted.