Not too sure about the damage in your pic Chris , but on the path beneath the bridge is what looks like one of the coping stones . This may have fallen (or been pushed!) off some time ago.I walk my dog through the Mops most days & it's been there as long as I remember.By the way , you may be interested to know that someone has put in an offer for the lodge at Bidston Court Gardens and they seem to be doing quite a bit of work on it .
Glad to hear that the Lodge is being looked after. Interesting to hear about the coping stone. I don't often visit, but I seem to remember that it's about there that the path looks as if there's been some damage in the past. Remember that until the 1830's this was the road from Birkenhead to Upton, before Ford Hill was built, so although it's steep, I'd expect the surface to be reasonably level. Around there as well, there's some evidence of old road metalling; chippings in asphalt I think, which has been broken up. Maybe it's all connected; next time you're there, see what you think.