The Pentagon is the largest office building in the world by office space. It is the main headquarters of the US Department of Defense and a potent symbol of US military might. The Pentagon was built during the WWII era and became the main target of Russian nuclear attacks during the Cold War. I love the story about the cafe at the complex's center which was the bulls eye. The only real attack the Pentagon ever suffered was on 9/11 when terrorists flew a plane into its flank.