Located in the green Osaka Castle Park, approximately 500 meters northeast of the castle tower, this is the largest hall in western Japan, consisting of an Arena Hall with a capacity of 16,000 people and a gymnasium-style sub-hall with a capacity of 500 people. Built in 1983 to commemorate the 400th anniversary of the founding of Osaka Castle, its greatest feature is the ability to set up a stage to suit a variety of events, including concerts, sports, exhibitions, ceremonies, and conventions. The adjacent building houses the Convention Hall, approximately 159 square meters in size, which can be used for various training sessions, seminars, interviews, informal meetings, and testing venues, the Castle View Hall, approximately 827 square meters in size, which can be used as exhibition space, and other conference rooms.