Oh great - has there been any investigation to a tunnel? It seems strange that it was built as such a distance from the house which makes one think there must be something. Old manors are well known for their secret doors and false walls. Used by servants and children playing hide & seek
Sorry, just edited my first reply! As far as I can tell there is no tunnel, but as I have only lived in this area for a few years, I will have to do a bit of ressarch to see if I can find out a bit more.