Answer:
isthmus
Step-by-step explanation:
An ishtmus is a portion of land that connects two large portions of land and separates two large bodies of water, ishtmus have historically very important and strategic places because the allow transit and whoever controls them controls the access to other trasnport routes for example center america is a good example of an ishtmus, the portion of land where the Panama Canal is a strategic place because it gives access to both the pacific and atlantic in a short amount of time.