The problems with using castle's are that those which still have walls are too close to civilisation, and you could be easily surrounded. For instanceGuitar Gamer said:take me with you!Portal Maniac said:I'll be off to Indianapolis, grab an aircraft capable of flying to Europe, along with a pilot. Then I'm off to find a castle in decent condition. Once I do, I'm going to border up the entrances and live in a castle surrounded by bodies.
Yup. Sounds fun.
my first stop would be "Buck fever" the hunting shop up the road, then to see if I cant highjack a ferry, spend as minimal time in the city as possible then I meet up with portal and either rob him or set to work fortify a castle with him or one adjacent to it, there's probably worse to spend the apocalypse with, might as well be a total stranger

All the zombies have to do is wait in the car park until the food supplies run out.
Those castle's which are more remote are those which have generally fallen to pieces and so of little defensive value.

Both these castle's are about a 3-4 hours drive from where i live, I've visited both of them. If forced to choose between an urban and a rural castle however, i think i would go for the urban one. Unless, the rural castle had a fully functioning moat. Most castle's don't have a moat anymore, as they have dried up. However i did find this castle here-

Surrounded by water, and with fully functioning wall's, seems great. The footbridge is the one point of entry which could be burned down, provided a boat is acquired for that instance it should be ok. The one problem however is that for me, it's a good six or seven hour drive to get to.
Anyway, in the instance of the zombie outbreak, that there is my fortress.