Complex sentence: Oldsum's landmark is an ancient thatched windmill whose antecessor presumably dates back to the year 1700, burned down 200 years later, was rebuilt and subsequently was in use until 1954.
Split into simpler sentences: Oldsum's landmark is an ancient thatched windmill whose antecessor presumably dates back to the year 1700. Though burned down 200 years later, it was rebuilt and subsequently was in use until 1954.