Princes' Park had a couple of unique 'secrets'...the tunnel (obliterated by the development at Park Nook) and the grave of Judy the Donkey. As it's quite hard to find, here's a pic with some background to help locate the grave. Or if you want a bit of fun, just ask someone to try and find it in the Park. (I've know people walk right past it and still not see it).
I have an early memory that there used to be raillings around the grave.
Judy gets a brief mention in one of Tom Slemens (him again) stories, published in the Liverpool Echo (a couple of years ago).
Pic from Feb 2004. The inscription is at Toxteth.net:
http://www.toxteth.net/places/liverp...20park%202.htm