I believe "Muranska planina" is in fact a plateau ("nahorna plosina" in Slovak} and not a plain ("rovina") from a geological and (especially) geomorphological point of view. A core of the Muranska Planina National Park consists of a limestone plateau - a relatively flat one, yet with higher altitude than the surrounding countryside. On the other hand, plains are characterized by their low altitude, rich soil, and they are generally alluvial origin. A typical plain is for example Podunajska rovina in Western Slovakia. That is why IMO the Slovak word "planina" in the national park's name should be translated as plateau ("nahorna plosina") and not plain ("rovina"). Muranska planina is also defined as a plateau at www.geologicacarpathica.sk, sbs.sav.sk, www.slovakspectator.sk, and some other websites (the first two of them are quite important because they are edited by the Slovak Academy of Sciences and the Carpathian-Balkan Geological Association).