Leading landscape gardener Humphry Repton designed the North garden in 1806 with a focus on creating hollows, hillocks and gently winding paths. As part of the WW2 war effort, part of the garden was requisitioned to host a barrage balloon in 1939 and railings were removed. The War Office took over the entire garden in May 1942 to station tanks, anti-aircraft guns and troops. In the 1970s the garden had to be re-landscaped when an underground car park was built beneath it. The now shallow soil presents interesting horticultural challenges and opportunities. The garden features some unusual trees, including a Brazilian pepper tree (Schinus molle) and a chinaberry tree (Melia azedarach).