This cache used to be part of two series of caches set around the borders of the parishes of Old Warden and Southill, Bedfordshire but with those series being retired, some of them, including this one, have been retained as stand-alone caches.
It used to be the case that at each point where a road breaks through the boundary to enter a parish, a cache has been placed. In the log book for each of these caches a piece of information existed which could be used to locate a bonus cache: The Interior for Old Warden and The Interior for Southill. These caches have now been archived.
Old Warden parish has a website at https://oldwarden-pc.gov.uk/. The parish is home to the Shuttleworth Collection which is an aeronautical and automotive museum located at the Old Warden Aerodrome.
Southill parish has a website at https://southillparishcouncil.gov.uk/. The parish includes Southill Park, former home of the Byng Family (including the notoriously court-martialled and executed Admiral John Byng, buried in Southill Church) and currently owned by the Whitbread brewing family, having been sold to Samuel Whitbread in 1795.
The boundary between Old Warden and Southill parishes runs along the road between Old Warden and Southill at this point, skirting Warden Warren.