https://www.quaddicted.com/files/idgame ... sblows.zip
This one might be worth a go.
Make your way from the middle of the map, pass the enemy outer fortifications, then there is two paths to flag from there.
(1) Go under the sign that says "Tower 3". Go straight into large opening. Go down the double spiral. Take either path, then either path again, and you are in the flag room.
(2) Take doorway to the side of "Tower 4" (Or behind it). Then drop down the shaft. Take either path, then either path again, and you are in the flag room.
Getting out, you will have to take the double spiral.
Lots of nooks and crannys to hide in. Escaping via the spirals could be challenging too.