As I am now receiving help to build this PvP arena, it has now been extended to an 80x80 block size.
I would also liek to point out that I am not using any plug-in to create this piece, every block has been dug out or placed by myself, thats why it looks like hardly any work is being done, but a lot of hours and minutes have went into this already.

Additional Notes

I am thinking about maybe making this a PvP/Parkour Map. In the latest picture you can see that there is a wall structure surrounding the PvP area that I think would be suitable for 4 different levels of parkour, each level starting after a tower and ending at the top of the opposite tower. Now that I have help from redstoners, I am hoping this will be possible.