Cathedral of St. Nicholas - baroque cathedral was built in the XVIII century by the Italian architect Andrea del Pozzo at the site of the ancient church of the XIII century. The interior of the cathedral are decorated with Italian masters, altar bishop made famous Slovenian master and architect J. Plečnik, and murals - brush Giulio Kvallio. Dome of the architect Gregor Maček was added later, and painted in the XIX century Matej Langusom.

Special attention deserve the doors of the cathedral, on which the modern Slovenian sculptures Mirsad Begic engraved picture with a history of the Diocese of Ljubljana, in conjunction with his creation for the visit to the capital of Slovenia, Pope John Paul II in 1996.