Claim: Kawagoe Castle, the closest castle to Kyoto to be accessible to visitors, had served as an important base of operations when the Hōjō clan sought to gain control of the Kantō; however, Hōjō Ujitsuna seized it in 1537 and took Edo castle in 1524.
Evidence: Kawagoe Castle (川越城, Kawagoe-jō) is a flatland Japanese castle in the city of Kawagoe, in Japan's Saitama Prefecture. It is the closest castle to Tokyo to be accessible to visitors, as Edo castle is now the Imperial palace, and largely inaccessible.