Complex sentence: The north end of the station is marked by a four-faced rectangular clock tower, which rises an extra story above the main roof; it is decorated with stone and terra cotta work that is repeated in plainer form throughout the station.
Split into simpler sentences: The north end of the station has a four-faced rectangular clock tower that rises an extra story above the main roof. It is decorated with stone and terra cotta work that is repeated in plainer form throughout the station.