I was doing a Bing image search for ‘Leeds Castle’ and one of the results led me to this fantastic site called InterfaceLift. It is well organised, searchable and you can pick the resolution to match your computer or laptop screen in a dropdown box under each image. It also has desktop themes, icons and more.
Here’s the ‘Leeds Castle Grounds’ image I found (1680 X 1050):
You can create a free account at InterfaceLIFT if you wish, but it is not necessary in order to access the images. With an account however, you can keep track of your favourite wallpapers, icons, and themes plus a lot more. Check it out!