I thought Dover Castle was Warwick Castle which I have visited and it's is pretty impressive, I didn't realise Dover also had such an outstanding one too, I guess it was front line of defence once though.
I managed 70% failed on ones I should have known such as Westminster Abbey which I've been to on a number of time living just 13 miles from London, but shot at that angle it could have been any very old cathedral. I took a calculated guess at others, such as the ones in Leeds and Liverpool, I've never been to either of those cities. On my list though!