When I was working on the farm in Lullington around 1980, this was a redundant farm building that modern machinery could not get in and out. It was restored in 1985. Around 1995 the new owner changed its name to 'Great meadow barn'. He presumably did'nt like 'Plonk barn' as a name.
I am pleased to say it has now reverted to it's former name, although no one who lives around here called it anything but 'Plonk Barn' anyway.
You are looking for a small clip top box capable of taking geocoins and small travelbugs. An ideal cache and dash for those in a hurry or wanting to keep a streak going. Parking is close.