Just a quick WAD file I did one afternoon when I wasn't busy.

Level name Enjay's Castle
Replaces E1M1

This level is designed with deathmatch playing in mind.  There are single
and co-operative play start points but it is best in deathmatch mode. I have
not included changes for the skill levels 'cos when you play deathmatch all
the bad guys eventually get wiped out anyway.  All the areas are accessible 
right from the start and there are lots of weapons ammo and medical stuff
lying around. The map itself is quite simple and most areas are big.

I heard that DOOM2 was going to be based mainly outside and at least some
of it in a castle type environment so I thought "I'll try that" and here is
the result.

I also decided to include some sounds in the WAD 'cos I thought the electrical
sounding doors and lifts did not seem right in a castle.

Known problems  I had a lot of "hall of mirrors" and invisible wall problems 
when making this level but I think they are all cleared up now.  
If you stand with your back hard against the northern most outside wall and 
fire a pistol, chain gun or shot gun the you seem to hit a wall that isn't 
there. This does not happen with the other weapons and your movement is not 
restricted - not a big problem so I left it.