Spain is a sovereign state located on the Iberian Peninsula in Southern Europe. It is a middle power and a major developed country with the world's fourteenth largest economy by nominal GDP and sixteenth largest by purchasing power parity. It is a member of the United Nations (UN), the European Union (EU), the Eurozone, the Council of Europe (CoE), the Organization of Ibero-American States (OEI), the North Atlantic Treaty Organization (NATO), the Organisation for Economic Co-operation and Development (OECD), the Schengen Area, the World Trade Organization (WTO) and many other international organisations. Spain has a "permanent invitation" to the G20 summits that occur generally once a year.