Complex sentence: The entrance halls included the Principal Entrance Hall of the villa and the great cross at that presided them, were destroyed in the middle of the 18th century in order to clear the surrounding of the town.
Split into simpler sentences: The entrance halls included the Principal Entrance Hall of the villa and the great cross that presided over them. They were destroyed in the middle of the 18th century in order to clear the surroundings of the town.