Complex sentence: Skipsea Brough is the location of Skipsea Castle which was built about 1086, the motte-and-bailey style castle has since been destroyed, however, impressive earthworks still remain.
Split into simpler sentences: Skipsea Brough is the location of Skipsea Castle which was built about 1086. The motte-and-bailey castle's buildings have since been destroyed, however, impressive earthworks still remain.