Pannonian island mountains

The Pannonian island mountains (Serbian: Panonske ostrvske planine, Панонске острвске планине, Croatian: Panonske otočne planine) is a name for mountains located in the southern Pannonian Plain, in the Serbian province of Vojvodina. They include Fruška Gora and Vršac Mountains. In prehistoric times, these mountains were islands of the ancient Pannonian Sea that disappeared about 600,000 years ago. Also, the mountains in region of Slavonia, in Croatia, like Papuk, Psunj, Požeška Gora, Krndija and Dilj were islands of Pannonian Sea.