The reason for this thread is to create a system that doesn't involve countless hours of towering to have fun doing so.

If done correctly and as stated, hopefully in a big open tower, then you can just grab your friends, and take the tower against everyone else trying to take/defend it. Hold it for as long as you can. In the end the guild with longest time holding it will end up winning a prize.
I would go with top 10 guilds get 2500 gralats each monthly, and top 3 guilds for season get a hat ticket, or maybe just top 1.

Also, I think I know an area where a new "longest hold" Tower can be set up at.

There used to be a dungeon in this area, and if it's not going to be used anymore, then this would be a great place for a Huge tower that can hold at least 5+ guilds (125+ ppl)