Dover is a town and major ferry port in the home county of Kent in South East England. It was picked as a location for Soulmerian dispatches because of it's small size (population: 28,000+). Major cities were too obvious a location choice. However, being in a smaller town means everyone knows everyone, which can make blending in even harder.
Also known as the "Key to England", the medieval castle was once a fortress that played a crucial role in the defense of the realm for over nine centuries. Now the castle is a nationally important historic building and a major tourist attraction.