Castle Tirion is a castle in an unknown stage of development. I've come across this article as well as a discussion group and a few other tidbits of information about it, but nothing current. It looks to be a project being put together by a member of the SCA, but I don't know to what extent it involves the rest of the organization; probably just a resource for volunteers. I'd qualify this as a "wish castle", but the viewable extent of planning done seems to qualify it out of that moniker.
EDIT: I've discovered the origin of the name by chance. Reading J. R. R. Tolkien's "The Silmarillion" reveals that Tirion is the castle in the West, sort of a utopian paradise for the characters in Tolkien's Middle-Earth stories.