Pannonian island mountains
The Pannonian island mountains is a term for isolated mountains scattered across the Pannonian Plain, chiefly its western and southern parts, in Hungary, Serbia and Croatia. In prehistoric times, these mountains were islands of the ancient Pannonian Sea that disappeared about 600,000 years ago.
The island mountains include:
;Croatia
- Central Slavonian Mountains:
- *Dilj
- *Krndija
- *Papuk
- *Psunj
- *Požeška Gora
- Medvednica in western Croatia
;Hungary
- Transdanubian Mountains of western Hungary:
- *Bakony
- *Buda Hills
- *Gerecse
- *Pilis Mountains
- *Vértes Hills
- *Velence Mountains
- Mecsek, in south Hungary
- Kőszeg Mountains, on Hungaria–Austria border
- Baranya Hills
;Serbia
- Fruška Gora
- Vršac Mountains
