Complex sentence: The Heseltines purchased Thenford House and its grounds in 1976 and over the next 25 years restored of woodland together with the walled garden, medieval fish-ponds and a lake.
Split into simpler sentences: The Heseltines purchased Thenford House and its grounds in 1976. Over the next 25 years they restored of woodland together with the walled garden, medieval fish-ponds and a lake.