There are plenty of 18x18s open in Malas outside Umbra and a few outside Luna... and there are 18x18s open in tram and fel as well... I know of at least one Fel keep spot at the moment, but I'm sure there might be more.
If interested in the one keep spot I know of, lemme know, I would be willing to show you where.
and sorry, i just read the subject line again... no castle spots I have seen as of lately.