Recommendations for Free Animal Shelters in Europe-MENA

A rare #journorequest. I’m writing a piece about volunteering abroad with animals, focused on dog/cat shelters in Europe, the Middle East and North Africa. Ideally independent operations and small NGOs that volunteers can contact directly and do for free, rather than voluntourism through a third party that costs money to take part in. I’d like recommendations of shelters to mention and I can of course name them and link to them in the piece. If you have firsthand experience of volunteering there and can vouch for them even better!