The term "Northern Border" typically refers to the boundary that separates one country from another to the north. In the context of the United States, it specifically denotes the border with Canada, which is the longest international land border in the world. This border spans approximately 5,525 miles and includes various terrains such as forests, mountains, and lakes. The Northern Border is significant for trade, travel, and security between the two nations. It features several official crossing points where people and goods can move between the U.S. and Canada. Additionally, the border is monitored by agencies like U.S. Customs and Border Protection to ensure safety and compliance with laws.