Yep I agree too. Although I am a foreigner I dislike that the English Heritage, saying is to protect and promote English spectacular historic environment, they are in reality,destroying the landscape to try to sell it.
I just went once and I dont have fancy to go again, as you say the barriers ,the coffee shops and selling, selling everything, finally I felt myself in the middle of Oxford street in London.

. Even £11.00 or more it is excessive).
The same impression I got when I visited the castle in Edinburgh. All was too shiny and clean that you dont believe that you are visiting an old castle or watching history. Finally I was wondering what it was reality and what was just ornement to made it more attractive to turists.
....mmm I think I will write all this to the english heritage
