Ljubljana is the capital and largest city of Slovenia. It is known for its academic population and green spaces, including the extensive Tivoli Park. The Ljubljanica river, curved and flanked by outdoor cafés, divides the old town from the shopping center. Ljubljana has several museums, including the National Museum of Slovenia, which has historic exhibitions, and the Museum of Modern Art, home to 20th-century Slovenian paintings and sculptures. The Lublianica river marks and divides the city center into two. On one side, the old part and the access to the castle, on the other the commercial and political part of the city. In the center, the square of the national poet, France Prešeren (1800-1849), which houses the main church, dedicated to the Franciscan Order. The architecture of the city contemplates a diverse mixture of styles. Its large sections, built after the Second World War, were designed by the Slovenian architect Jože Plečnik. The city also has a great Austrian influence, visible in some districts of alpine architecture. Ljubljana Castle is a medieval castle located at the top of the hill in the center of the city.