Complex sentence: The chosen site, in northeastern Maine within both Limestone Township and Caswell Plantation, was the closest point in the Continental United States to Europe which made sure that the location would provide high strategic value during the Cold War.
Split into simpler sentences: The chosen site, in northeastern Maine within both Limestone Township and Caswell Plantation, was the closest point in the Continental United States to Europe. This location would provide high strategic value during the Cold War.