Like many local authorities, Hendon built air-raid shelters in public parks to provide residents with protection from enemy attackes in World War II. One such set of shelters was in Sunny Hill Park, built towards the end of 1939.
In July 2010, the shelters were subjected to an archaeological excavation led by University College London and supported by HADAS (Hendon And District Archaeological Society) and Subterranea Britannica. The excavation is written up by the Directior of the dig, Dr Gabriel Moshenska, in Subterranea issue 24.