The Bastle Tower
There was a medieval tower, almost a 'keep', at the southwest corner of Farnisham town, overlooking the harbour. Cromwell's Parliament ordered its demolition, but it was never fully carried out because of lack of funds and interest. However, the stub of what was left was used as a warehouse until 1882 when Lord Farnish had it rebuilt as a fitting venue for the governor of the island, Major Prettyboy.
The structure is a small rectangular building with four round corner towers crowned in the French chateau style with chemin de ronde parapets and conical roofs, with connecting semicircular chord walls. It looks rather odd, because the architect never rebuilt the third story, and a proper 'French' castle needs to be very tall. The current function of this building is to serve as the Farnisham town hall -- register births and deaths here, get marriage licences, etc. -- and is also the residence of the county clerk, here called the 'Justiciar' (who is, de facto, the effective governor of the whole island, Mother Mitherglew's pretensions notwithstanding).
The entrance is a small door leading into a vaulted lobby decorated with portraits of past notables of the island. On one side is a waiting room (you can get married here too), out of which is the circular staircase to the upper floors and down to the storage vault under the courtyard. There is also a tiny public WC. On the other side of the lobby is the 'service room' where one makes one's request. Behind the service room is the office, and in the tower is the archive chambers. On the east side there are secretarial quarters, parlour, mess room, etc. And between the southern towers is a small but lofty and ornate meeting room for the island 'parliament' (actually the day-to-day cabinet conference room, since full sessions are held in the nearby castle tower, and the Farnfork Arms pub, ahem).
The second story consists of several offices for bureaucrats, another floor of archives, and the official Justiciar's residential quarters. There is a balcony over the entrance that is occasionally used for public speaches and exhortations. Above this floor are windowless attics in the tower tops (and perhaps some secret offices used by British Intelligence that we don't know about, but have heard rumours of).
To the east of the Bastle is the Tower/Court structure and the castle itself on the Hill, atop which is Farnisham Castle.
On the site of the northwest tower of the old town wall is the Museum and Public Library.