Complex sentence: The Ogrestone or Thurgartstone near Dunlop in East Ayrshire is thought to have been a rocking stone, however soil has built up around its base over the years and now prevents any rocking motion.
Split into simpler sentences: The Ogrestone or Thurgartstone near Dunlop in East Ayrshire is thought to have been a rocking stone. However soil has built up around the base of the Thurgatstone over the years, which now prevents any rocking motion.