Trnje Festival is an annual two-day festival which takes place some time in July in a clearing surrounded by the pine forest in Trnje village near Pivka (Postojna). It is a festival of alternative and unconventional music of many musical genres featuring unknown music bands which present new initiatives against the trends of consumerism. The first festival took place in 1998 and since then it has gained a notable status among alternative summer festivals that are affordable yet offer a rich and diverse musical programme. The organisers like to refer to Trnje Festival as "a festival for those who cannot afford to go to the seaside". It is organised by a joint team from Postojna Youth Centre and Pivka House of Culture.
Maintaining its relatively low profile, the festival offers a relaxed and friendly atmosphere in one of the most natural environments possible. The festival has featured Slovene and foreign artists covering music genres from electronica, rap, rock, ska, punk, hardcore to death metal, among them: Ana Pupedan, Analena, Ani(e)mo(a)tion, Bolesno grinje, Damir Avdić, Drugi disko, Let 3, Low punch, Marko Brecelj, Muškat Hamburg, Nikki Louder, New Wave Syria, Noctiferia, Pridigarji, Psycho-path, Radical dub collective, Repetitor, Srečna mladina, Stekli psi, Superhiks, Štefan Kovač Marko Banda, Žoambo Žoet Workestrao, and many more.