was one of the primary castles of Oda Nobunaga located in the Azuchi neighborhood of the city of Ōmihachiman, Shiga Prefecture. The site of the castle was designated a National Historic Site in 1926, with the designation upgraded to that of a Special National Historic Site in 1952. The castle is located within the grounds of the Biwako Quasi-National Park. Azuchi Castle was built from 1576 to 1579 on Mount Azuchi on the eastern shore of Lake Biwa in Ōmi Province. Nobunaga intentionally built Azuchi Castle close enough to Kyoto that he could watch over and guard the approaches to the capital, but outside Kyoto so his fortress would be immune to the fires and conflicts that occasionally consumed the city. Azuchi Castle's location was also strategically advantageous in managing the communications and transportation routes between Nobunaga's greatest foes – the Uesugi to the north, the Takeda in the east, and the Mōri to the west. Azuchi Castle was demolished in 1582 by Akechi Mitsuhide after his assassination of Nobunaga in the Honno-ji Incident. The Azuchi-Momoyama period of Japanese history partially takes its name from Azuchi Castle. History Niwa Nagahide had responsibility for constructing the castle, which began in 1576 and completed in 1579. Unlike earlier castles and fortresses, Azuchi was not intended to be a military structure alone, cold, dark, and foreboding. Nobunaga intended it as a mansion which would impress and intimidate his rivals not only with its defenses, but also with its lavish apartments and decorations, flourishing town, and religious life. The keep, called tenshu (or tenshukaku), rather than being the center of the castle's defences, was a seven-story building containing audience halls, private chambers, offices, and a treasury, as though it were a royal palace. All seven stories were decorated by Kanō Eitoku. In addition to being one of the first Japanese castles with a tower keep, Azuchi was unique in that its uppermost story was octagonal. In addition, the facade of Azuchi, unlike the solid white or black of other castles, was colorfully decorated with tigers and dragons. There were five main militaristic features of Azuchi Castle that differentiated it from earlier castle designs. Firstly, it was a massive structure, with the walls of the castle ranging from 5.5 to 6.5 meters in thickness. The second feature of Azuchi Castle is the predominant use of stone. The walls were constructed from huge granite stones fitted