Poland is a country located in Central Europe, bordered by Germany to the west, Czech Republic and Slovakia to the south, Ukraine and Belarus to the east, and Lithuania and the Russian enclave of Kaliningrad to the north. The capital and largest city is Warsaw. The official language is Polish and the population is around 38 million. The economy is based on services, manufacturing, and agriculture. Poland has a rich history and culture, with famous landmarks such as the Wawel Castle in Kraków, the Old Town of Gdańsk, and the historic Wieliczka Salt Mine. Poland is a parliamentary republic with a president as the head of state. The country joined the European Union in 2004.