Complex sentence: This wing consisted of three rooms: a central room where the four tablets--heaven, earth, ancestor, and teacher--were worshipped, and two rooms attached to the left and right, which were bedrooms for the grandparents.
Split into simpler sentences: This wing consisted of three rooms, a central room where the four tablets, heaven, earth, ancestor, and teacher, were worshipped. There the two rooms attached to the left and right were bedrooms for the grandparents.