A nondescript square building that has room for two guards that change shift every 8 hours.  There's a fireplace inside, food enough for a week and a large earthenware jug of water for cooking and drinking.
Guard Shack, Outside Tower
a knight, captain, or general that may oversee the guards.
guard
I am a guard who watches for things at night. I live in a castle. I do not enjoy speaking with people.
Why, sir, I am a guard. good it means you are my boy Yes sir. you know we had to relocate recently due to the fight breaking open part of our facilities. I was out that day. you incompetent guard Get off of me! I was planning to forgive you but now you will sleep in the dungeon for 2 months  You attacked me! because you don't know how to respect your superior  I did nothing! You are fired!