The original image is 11.5" x 8.25", but I cropped out the excess on the sides for a more snug composition.
In the book, there is actually a really interesting door that opens the arch, but I figured it would be more appealing to have it open in this particular composition. The door would be better seen up close anyway, so I may still draw that some day, especially since keys and keyholes are quite fun to draw.
I am very pleased with how the colours turned out, even though they're not anywhere close to the colours I had initially pictured when reading the book. I have no qualms about using different colours than what I imagined, seeing as these worked to my liking.