Follow up for Zanzibar/Tanzania, @elmarconi.
The NBC ATMs didn’t accept MasterCard, Visa/Visa Plus only, in this case. I cannot tell if that’s the case in general.
The Barclays ATM wanted to charge 15.400 TSH (about 5,85 EUR) access fee. 
People’s Bank of Zanzibar is only for locals anyways. 
So the only good one was…
KCB
Cine Afrique Building, Zanzibar City 1234, Tansania
https://maps.app.goo.gl/GtC22JFPPAUra4VZ8