Complex sentence: A new (fourth) City Hall in Copenhagen, Denmark, was built between Gammeltorv and Nytorv in 1728 on the foundations of its predecessor which had been destroyed in the first Great Fire of Copenhagen earlier that same year.
Split into simpler sentences: A new (fourth) City Hall in Copenhagen, Denmarkm was built between Gammeltorv and Nytorv in 1728. It was built on the foundations of its predessor which had been destroyed in the first Great Fire of Copenhagen earlier that same year.