Complex sentence: The area of Belfast City centre now known as Smithfield and Union extends from North Street to Frederick Street and is bounded by Royal Avenue/York Street and Carrick Hill/Millfield and it is the axis of Belfast's cultural corridor and heritage trail.
Split into simpler sentences: The area of Belfast City centre now known as Smithfield and Union extends from North Street to Frederick Street and is bounded by Royal Avenue/York Street and Carrick Hill/Millfield. It is the axis of Belfast's cultural corridor and heritage trail.