The capital city of Slovenia is Ljubljana. It is known for its picturesque landscapes, historic architecture, and vibrant cultural scene. The city, which sits along the Ljubljanica River, features a charming old town with a mix of Baroque and modernist buildings, as well as beautiful parks. Ljubljana is also recognized for its sustainable practices and has been designated as a Green Capital of Europe. Additionally, the city's rich history dates back to Roman times, highlighted by the ancient castle that overlooks it, making it a popular destination for tourists and a central hub for Slovenian culture and education.