Can't stop a determined cat

I have a second floor porch that my kitties like to hang out on on these nice cool nights. However, there is a small ledge accessible perpendicular to the narrow side of the porch rail. On the small ledge, the cats (even fat ass Magnum) walk along it and visit the mean neighbor's porch.

If that was the end of the mischeif, I could live with that. However, Adira summoned the courage to jump to the tree five feet away from the ledge, and climbed down the tree. I don't think she'd be able to retrace her steps to return to my porch (I had to rescue her at 2:00 AM when I realized what happened).

So there has been an on-going war trying to make a barrier of the small ledge, and Adira trying to bypass it. What had lasted a while was to take some fabric, secure both ends over the ends of cafe curtain rods. Then place one rod just above the railing, and the other a couple feet above the railing. However, early in the AM, Adria succeeded in dragging down the upper rod. Don't know how she did it, but it made a lot of noise; I guess she just jumped and dragged the fabric down with her claws.

So I put the upper curtain rod even higher (it's about 6 feet high now). And the lower rod is about a couple inches above the porch railing. I didn't want to be woken up again, so I shooed her inside and closed the porch door. I'll see if she can tear it down after work today.

If Adira could prove to me that she could make her way back up to the patio, I still would be working on an effective barrier for two reasons. First is that Adira will NOT have anything to do with a collar or harness. So if someone else stumbled on to the adorable fluff ball, they wouldn't know how to return her to her home. The second reason is that Magnum throws a hissy fit when Adira re-enters the patio, and (loudly) attacks her. It took several shots of my water bottle to chill him out after she returned to the patio after tearing down the barrier this AM.