Can someone tell me the differences between castles???

[st.patrik]

Like Taqwus said - there are a lot of towers which fire at your enemies on the mountain citadel, and they have to run through a long narrow passageway flanked by towers at point-blank range. The dark citadel doesn't have any towers and just a simple opening - no corridor of death approach.

So there is a huge difference, if you actually use your castle ever for defense. If you're facing a nation like Ulm in a mountain citadel and you have access to spells like 'sleep cloud' or 'poison cloud' or pretty much any cloud you can hold them for a long long time by choking up the passageway with these 'clouds' and watching them take their effect. The best part is, as soon as the people in front of them die, the others in the opposing army will run straight into the poisonous clouds and die themselves. Caution, castle defenders not included.