The Bordeaux wine region is broadly divided between the left and right banks of the river Gironde. St Emilion is the best known of the right bank wine regions with Margaux the best known of the left bank. Soils and climate distinguish the two areas on each side of the river. Left bank soils (pebbles/gravels) suit Cabernet Sauvignon (with some merlot) and the climate has a marginally more Atlantic influence - wetter and slightly cooler . Right bank soils comprise clays and limestone and are better suited to Merlot (and some Cabernet sauvignon). Here the climate is slightly warmer and the air less moist.