Originating in 1953 with Ljubljana's oldest festival, the Ljubljana Summer Festival, Ljubljana Festival public cultural institution is an agency of the Ljubljana Urban Municipality. Apart from its continued central duty of organising the annual Summer Festival. Festival Ljubljana organises, or takes part in organising, numerous other projects that contribute to the cultural image of the capital. Other traditional events within its remit include Slovene Music Days, the Young Virtuosi music programme, an International Contest of Opera Singers known as Ondina Otta organised together with the Slovene National Theatre (SNG) Maribor, and the Festive December programme, in which short concerts are given at Križevniška Church by Ljubljana music school students. Many of its events are held at Križanke, a space designed in 1952 especially for the Ljubljana Festival by renowned architect Jože Plečnik.