Consisting of ten provinces and three territories, and spanning over 9.9 million square kilometres, Canada is the world's second-largest country by total area. Its common border with the United States is the longest land border in the world. Canadian wine has been produced for over 200 years, and today there are eight viticultural areas, five in British Columbia and three in Ontario. The two largest wine producing regions in Canada are the Okanagan Valley and the Niagara Peninsula. Although not a major wine producer by global standards, the Canadian wine industry has evolved into a niche maker of internationally-respected icewines and late harvest wines due to the cool-climate influences. Cool climate viticulture areas in the northwestern US, New Zealand and Germany as well as Canada are suitable for growing Vitis vinifera varieties such as Riesling, Chardonnay and Pinot Noir grapes. While Canada's wine-making regions are not homogeneous, Merlot, Cabernet Sauvignon and Cabernet Franc are also popular Vitis vinifera varieties.