Yes due to the popularity of Downton Abbey, new this year is a Downton Abbey Film Locations Tour that is really good and also proving very popular
I have posted more details below
Here is some more information on the filming of Downton Abbey from Highclere Castle that is the fictional Downton Abbey
Here is the tour we are recommending
Downton Abbey Film Locations Tour
We found this and thanks to them at SightseeingTours.co.uk