Fleet Activities, Yokosuka comprises 568 acres and is located 43 miles south of Tokyo at the entrance of Tokyo Bay and approx ... imately 18 miles south of Yokohama. Yokosuka is on the Miura peninsula in the Kanto Plain region of the Pacific Coast in Central Honshu, Japan. CFAY is the largest overseas U.S. Naval installation in the world and is considered to be one of the most strategically important bases in the U.S. military. read more