Visitors to the Vatican should come prepared - with lots of cash. Italy has blocked the use of credit and debit cards in the tiny city state. Rome's concerned about a lack of financial transparency there. The move is a blow for the Holy See, as sales of souvenirs, stamps and admission tickets to people visiting attractions like the Sistine Chapel is one of its biggest sources of income. In 2011, 5 million visitors brought in over 91 million euros.