This map features a fictious castle built on top of a canyon. I was aiming for a hard siege, and that is why I chose such terrain. But I was also aiming for a map that would be chalenging both when attacking and defending the castle. And that brought the difficulty down. I found out that it's really hard to make a siege that is both balanced and challenging, so I made a balanced map for people of my skill (noobs). Well, at least I think that it's balanced :p
I am downloading the map now, but don't get caught up in the idea a Siege Map has be challenging as Attacker AND Defender. That isn't what "balance" means. Design your Castle to be Sieged or Defended. Then tell the players what their task is in the storyline. "Balance" refers to how even the fight is based on how you are supposed to play the scenario.