求翻译：故宫占地72万平方米，屋宇9999间半，建筑面积15.5万平方米。为一长方形城池，四角矗立、风格绮丽的角楼，墙外有宽52米的护城河环绕，形成一个森严壁垒的城堡。建筑气势雄伟、豪华壮丽，是中国古代建筑艺术的精华。是什么意思？

National Palace Museum covers 720,000 square meters, the buildings between 9,999 half, 155,000 square meters. For a rectangular city, four corners stand, style, beautiful Tower, outside the wall of 52 meters wide moat around to form a castle of the demarcation between each other is distinctly marked