Alva Castle, Estalia
The estuary of the River Ramat is very marshy, and the river is not very navigable in this area (without dredging canals), although it is rather important as a trade conduit farther south. Alva Island and the main part of the estuary was granted to Gorgefus Duffus, Mayor of Liga, in 1640 by Himzip-tol-Ten in his early days as Chancellor (as some early effort at some strategic shenanigans), and that area ceded to West Estalia. Duffus then built the castle within the bailey of an old Estalian rath that was already on the site; it protects the river entrance against those who would intrude. However, it has never played any important historical role and is now the summer residence of the Mayor of Liga when he can stand the midges.
This castle is very small and not complex (don't be misled by all the printing on the plans, which makes it look complicated). There is a small ridge of granite and gravel in the estuary that has built up a couple of permanent 'aits'. Alva was built on the most prominent hill in the Bronze Age as a simple rath, or roughly circular stone enclosure that would have contained wattle-and-daub huts. Duffus restored the old walls and built a house transecting the enclosure. It is no mighty fortress, but well-protected by its isolation. The basic plan is based on a two-story Great Hall with bedroom and parlor wings at each end and a kitchen range (with cellars under) projecting from the middle; main defence was a gatehouse on the south side. The only unusual feature of this typical 'shell-keep' type castle is the upper level wooden gallery running around two sides of the great hall. The wall-walk and curtain wall is at different heights, depending on the vulnerabilty of each aspect -- the most exposed, being on the entrance side facing the ferry dock and boathouse, has four levels. The gatehouse is also well-protected and the postern gate has a couple of guardrooms over it.
It is a nice retreat for the Mayor of Liga, plain and grim as it appears from the outside and sited in a swampy, bug-ridden estuary. Home farm on the island supplies most of the needs of the castle. Fishing is a major recreation here, as is bird-shooting. Also, if not that important, entrance to the River Ramat, in its most navigable channels, is overseen and protected to some extent though the castle is not a fortress.