Complex sentence: The building is symmetrical in layout and has a clock tower in the middle and a watchtower in each corner and was gazetted by the Macau government as an architectural heritage site (Decree No.83/92/M).
Split into simpler sentences: The building is symmetrical in layout and has a clock tower in the middle and a watchtower in each corner. It was gazetted by the Macau government as an architectural heritage site (Decree No.83/92/M).