Marunouchi (丸の内) is a commercial district of Tokyo located in Chiyoda between Tokyo Station and the Imperial Palace. The name, meaning "inside the circle", derives from its location within the palace's outer moat. It is also Tokyo's financial district and the country's three largest banks are headquartered there. In 1590, before Tokugawa Ieyasu entered Edo Castle, the area now known as Marunouchi was an inlet of Edo Bay and had the name Hibiya. With the expansion of the castle, this inlet was filled, beginning in 1592.