The fourth marquess, John Crichton-Stuart, was an enthusiastic restorer and builder and commissioned a major restoration project between 1928 and 1939. The stonework was carefully repaired, with moulds made to recreate missing pieces. The Inner East Gatehouse was rebuilt, along with several of the other towers. The marquess carried out landscaping work, with the intent of eventually re-flooding the lakes, and thanks to several decades of purchases was finally able to demolish the local houses encroaching on the view of the castle.