After creating my Minas Tirith invasion map (Minas Tirith by Bismuth #686) I wanted to try to use the same map for an Attacking Siege.
I made a few modifications to the original map, including adding towers with mangonel and ballista.
You will need to play on EASY to start with the maximum number of units - approx 500. If you find this too easy try playing on NORMAL.
I have not tested this as a defending siege - only as ATTACKING. Originally I had set as the victory condition to eliminate all enemy units but currently victory is obtained by killing the Lord of Minas Tirith.
You control the attacking hoards of Mordor. Enjoy!
(For more detailed background on the city of Minas Tirith please see my notes for Invasion #686)