What's a blockade location

Blockade: the isolating, closing off, or surrounding of a place, as a port, harbor, or city, by hostile ships or troops to prevent entrance or exit.

"Ablockade is an effort to cut off supplies, war material or communications from a particular area by force, either in part or totally. A blockade should not be confused with an embargo or sanctions, which are legal barriers to trade. It is also distinct from a siege in that a blockade is usually directed at an entire country or region, rather than a fortress or city. While most blockades historically took place at sea, blockade is still used on land to prevent someone coming into a certain area."