Thoughts: I have been inspired by and taught many gardening tips from my friend Kristy. She has a spectacular yard. Her neighbor next door has an equally beautiful yard. The have planted a row of espaliar fruit trees that have formed a living fence between their properties.
Things: Training espaliar trees was a technique popular in the middle ages in Europe to produce fruit inside the walls of a typical castles courtyard without interfering with the open space and to decorate walls. They are trained to grow flattened out. They are also perfect along a fence. They are smaller fruit trees yet still bear fruit.
I have planted 2, they are both apple. A cherry espalier tree is on my wish list for this summer...
Plant one at your castle.