Wow, I am incredibly late to see this. I might as well reply anyway, even if you may have your answer already.

I'm not sure if I can do any medieval maps any time soon, I haven't found any inspiration or anything to come to make any more maps recently. I might sometime in the future attempt to make one, but I really don't know. The castle might be a little hard to make an interior for since the towers are static models and couldn't be carved out in the editor.

As for the program, I used Hammer, which comes packaged with Team Fortress 2 ( which can be found in the [ ... Steam\SteamApps\common\Team Fortress 2\bin ] folder as hammer.exe or hammer.bat ). As for the buildings, I sculpted them myself in the editor. They're not exactly models, they're brushes, which are only made in the editor and not imported.

Don't worry about it I'm just glad you replied. Well since you can't do any of that other stuff, do you think it'd be easy to make a night version of this map? I really enjoy using it for a comic series I'm working on, but when I just tone down the camera lighting in SFM it doesn't exactly do the trick. If it isn't too much trouble, could you possibly make a night version? I'm just really in love with your amazing work, but I'd understand if you couldn't.

Hey whenever you can it is appreciated, this map is very well made and I am currently making a wallpaper on it. Thank you

Is it just me or is the map amazing

It's amazing