The biggest castle in the world at the middle ages period.
In 1590, Odawara Castle which was the home ground of Hojo, the strongest Daimyo (feudal lord) in Kanto Area, was surrounded by the military of Hideyoshi Toyotomi.
Hojo was not only keep negotiating with Toyotomi but also preparing for the battle. Hojo's first action was making his castle stronger and bigger. He made a great walls to surround his entire city. The wall was 9 km length which made the Odawara Castle the biggest castle in the world at that time.
Negotiation failed. Hojo put his main military in the Castle, and set the defense for all brunch castle around Odawara Castle.
The number of Toyotomi's military was 220 thousands. Ieyasu Tokugawa was taking the lead of the main companies. Toyotomi was also used his navy to make a complete siege. In the Hojo side, about 60 thousands of his military and villagers barricaded into the castle.
Almost, all the Sengoku Heros joined this Odawara Battle, and the battle kept running more than three months. Toyotomi prepared well for food and money for this battle, and built new castle nearby Odawara Castle. Hojo's tactics was moving his main force through his brunch castles and defeating one by one from his brunch castles. However, Toyotomi kept Hojo's main military at Odawara Castle and defeated all Hojo's brunch castles. Hojo finally gave up fighting, and opened the gate for free.
After Odawara Battle, all the other Dimyos who was not obeyed Toyotomi yet acknowledged fealty to Toyotomi, and this was the end of Sengoku Period by the domination of Toyotomi.
During the Edo Period (1603 -1867), various types of castle gates stood on the castle grounds. The gate which is located in the east corner of the central bailey was the main entrance and the most strategic place for the defense of the castle. This gate was named Tokiwagi ("Evergreen"), because there were old pine trees nearby. The feudal lord believed that the pine trees would stand forever, and wished the same for the castle.
At the beginning of the Meiji Period (1870), most of the structures on the castle grands, including the original gate and Tenshu, were dismantled. The present gate was rebuilt in 1971 and the Tenshu was rebuilt in 1960.
Akagane Mon, the main entrance of Odawara Castle's second bailey, was built in the early Edo Period (1603 - 1867). It was demolished at the beginning of the Meiji Period. The present gate was rebuilt in 1997 in the style of the original structure based on excavation findings and old drawings.