Free Traffic Legal Advice

I received this PCN, for entering a restricted zone and I know now that I will receive another soon probably as I took the same route exactly one week after. Obviously I didn't know this was a restricted zone until I received the PCN. The restricted zone begins right after a left turn off of a small roundabout with no prior warning on the approach road. I revisited the area on foot today to take photos (attached) and as you can see, there is no warning on the approach road, the signs are high up and just after the roundabout making it dangerous to back out of the turn once committed and the left hand sign is also partially obscured by a speed limit sign.

Any advice you can provide or the likely hood of me having grounds for a succsessful appeal would be much appreciated.













Google map location https://maps.app.goo.gl/LUq5wshD6a82fEAA7