Slovakia (/sloʊˈvækiə, -ˈvɑː-/ ( listen); Slovak: Slovensko [ˈslɔʋɛnskɔ] ( listen)), officially the Slovak Republic (Slovak: Slovenská republika, listen (help·info)), is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, the Czech Republic to the west, Hungary to the south, and Austria to the southwest. Slovakia's territory spans about 49,000 square kilometres (19,000 sq mi) and is mostly mountainous. The population is over 5.4 million and consists mostly of Slovaks. The capital and largest city is Bratislava, second largest city is Košice. The official language is Slovak.