Poland is a developed market, and a middle power; it has the sixth largest economy in the European Union by nominal GDP and the fifth largest by GDP (PPP). It provides very high standards of living, safety and economic freedom, as well as free university education and a universal health care system. The country has 17 UNESCO World Heritage Sites, 15 of which are cultural. Poland is a member state of the Schengen Area, European Union, European Economic Area, the United Nations, NATO, the OECD, the Three Seas Initiative and the Visegrád Group.