In San Marino they use the Euro, though they are not a member of the European Union.
The San Marino Lira, which was the previous currency, is rare and is valuable to coin collectors.
50% of the economy is based on tourism, other industries include banking, pottery, and electronics. They also make wine and cheese there.
Postage stamps from San Marino are only valid for shipping within San Marino. Itallian postage is used for shipping elsewhere.