Complex sentence: Many of these, particularly Becher's Brook, The Chair and the Canal Turn, have become famous in their own right and, combined with the distance of the event, create what has been called "the ultimate test of horse and rider".
Split into simpler sentences: Many of these fences, particularly Becher's Brook, The Chair and the Canal Turn, have become famous in their own right. These, combined with the distance of the event, create what has been called "the ultimate test of horse and rider".