What about using ATM debit/credit cards in Crimea?

Using credit debit cards in Crimea

Even though Crimean shops do not accept debit/credit cards issued outside of the Russian Federation, this is not going to pose a problem when visiting the peninsula. You should simply ask your Yucca Tours guide for assistance. We also recommend bringing some cash with you. We advise against trying to use payment cards issued outside Russia for danger of blocking.