Caledonian Edinburgh Castle at the Rising Sun, Redditch

You could have a lot of fun building a brewery inside a castle. Firstly, the dungeons would be the perfect place to condition the beer. You could have all the fermenting taking place away from your guests; and even have traditional knights dressed in armour to guard those secret recipes! Next would be the banquet hall where you could have your guests seated at long benches raising toasts to the blessed beer. If you’re feeling generous, you could have fountains for your guests to dip their glasses into. Your moat could be filled with beer; though this may be more of an attraction than a deterrent (unless you brew a particularly bad batch to poison your enemies). If an invasion occurs, you could even hose your enemies away. Then it’s just a case of setting up an underground system to connect your castle to the pubs in the town (assuming that they’ll drink enough of the stuff).