Why doesn't the main entrance of Xi 'an Academy of Fine Arts open?

Rules handed down from generation to generation. The gate of Xi Academy of Fine Arts has not been opened for a long time, which is a rule handed down from a long time ago. The main entrance is generally closed to people and traffic, and pedestrians and vehicles generally take the doors on both sides. Xi 'an, referred to as "Gao", was called Chang 'an and Haojing in ancient times. It is the capital, sub-provincial city and megacity of Shaanxi Province.