Complex sentence: The Ming dynasty saw the construction of the Liaoning section of the Great Wall through Huludao, and it was during this time that the town of Xingcheng was fortified with its defensive wall which still stands today.
Split into simpler sentences: The Ming dynasty saw the construction of the Liaoning section of the Great Wall through Huludao. During this time the town of Xingcheng was fortified with a defensive wall which still stands today.