[dairylee]

Although it's not quite sheep Newcastle has a Town Moor (Larger than Central Park) which has grazing cattle. There's also a farm not too far from the city centre which has grazing sheep.

https://en.wikipedia.org/wiki/Town_Moor,_Newcastle_upon_Tyne

https://www.bbc.co.uk/programmes/p03hm60d/p03hm2x8

https://maps.app.goo.gl/vojeS3eDTFznpYwMA

[muziq]

The Ouseburn Farm in Newcastle (your last link) is a great place :)

[gambiting]

I was going to say, I'm sure Desmond Dene has sheep there.

[rantallion]

If you mean Jesmond Dene, there's a petting zoo with a few small beasts and birds. I know they have a couple of breeds of goat but I don't recall seeing any sheep on my last visit (within the last month).