The Pentagon was first conceived at Arlington Farms, where a five-sided plot inspired its unusual shape and the working name New War Department Building, or the more informal "pentagonal building."

However, when President Franklin D. Roosevelt moved the project to the former Hoover Airport to preserve cemetery views, the design stuck – it was too costly to change. By 1942, the building was officially christened The Pentagon, a name as distinctive as its form.

Now discover the secrets of the world’s most famous buildings

Famous American landmarks that almost had completely different names