Complex sentence: The fort was modified a number of times in the late 17th and early 18th centuries, such as linking the fort directly to the cavalier and filling in part of the ditch burying some of the original ramparts in the process.
Split into simpler sentences: The fort was modified a number of times in the 17th century. In the late 17th century, the fort was directly linked to the cavalier and part of the ditch was filled in burying some of the original ramparts in the process.