The Canada-United States Border is the longest international land border in the world, stretching over 8,891 kilometers (5,525 miles). It separates Canada to the north from the United States to the south, running through various terrains, including forests, mountains, and rivers. The border is marked by a combination of natural features and man-made barriers. This border is significant for trade, travel, and cultural exchange between the two countries. Numerous crossings allow for the movement of people and goods, making it a vital economic link. Both nations work together to ensure security and facilitate smooth transit across the border.