Odawara Castle (Odawara-jō) is a landmark in the city of Odawara in Kanagawa Prefecture, Japan. Odawara was a stronghold of the Doi clan during the Kamakura period, and a fortified residence built by their collateral branch, the Kobayakawa clan stood on the approximate site of the present castle. After the Uesugi Zenshu Revolt of 1416, Odawara came under the control of the Omori clan of Suruga, who were in turn defeated by Ise Moritoki of Izu, founder of the Late Hōjō clan in 1495. Five generations of the Late Hōjō clan improved and expanded on the fortifications of Odawara Castle as the center of their domains, which encompassed most of the Kantō region.
During the Muromachi period, Odawara Castle had very strong defenses, as it was situated on a hill, surrounded by moats with water on the low side, and dry ditches on the hill side, with banks, walls and cliffs located all around the castle, enabling the defenders to repel attacks by the great warriors Uesugi Kenshin in 1561 and Takeda Shingen in 1569. However, during the Battle of Odawara in 1590, Toyotomi Hideyoshi forced the surrender of the Late Hōjō clan through a combination of a three-month siege and bluff. After ordering most of the fortifications destroyed, he awarded the holdings of the Late Hōjō to Tokugawa Ieyasu.