Complex sentence: The expedition discovered that the large buried supporting oakwood poles of the former bridge was still intact and they also found remains of an old road on the north side of the bridge as well as traces of an old hollow way in the woodland hills surrounding the meadows.
Split into simpler sentences: The expedition discovered that the large buried supporting oakwood poles of the former bridge were still intact. They also found remains of an old road on the north side of the bridge as well as traces of an old hollow way in the woodland hills surrounding the meadows.