Complex sentence: The original Wembley Stadium (formerly known as the Empire Stadium) was a football stadium in Wembley Park, London, which stood on the same site now occupied by its successor, the new Wembley Stadium.
Split into simpler sentences: The original Wembley Stadium (formerly known as the Empire Stadium) was a football stadium located in Wembley Park, London. It stood on the same site now occupied by its successor, the new Wembley Stadium.