San Marino (officially the Republic of San Marino) is a micronation situated on a small, rocky isthmus in the southernmost point of the Adriatic Sea. The republic has a population of just over 3,000. San Marino is ruled by a Consiglio di Stato, with a president and a unicameral Chamber of Deputies. The country's economy is based mainly on services and small trade. San Marino is a member of the United Nations, the Council of Europe, the Organisation for Economic Co-operation and Development, the World Trade Organization, and the International Monetary Fund.