The Serbo-Macedonian Massif (SMM) is a composite crystalline belt within the Eastern European Alpine orogen. It extends from the Pannonian basin in the north to the Aegean Sea in the south. The central part is located in southeastern Serbia, southwestern Bulgaria and eastern Macedonia. The rocks are mostly medium- to high-grade metamorphic rocks except for the low-grade metamorphic Vlasina Unit. This unit is geographically known as the Osogovo–Belasica mountain chain, also known as the Rhodope range, this name originates from Bulgaria across the border.
The interpretation for us is simple: there is no limestone, probably a little marble, but in general a low chance for karst caves. On the other hand, there are mineralizations and thus mining, but so far Northern Macedonia has no show mines. We have currently no underground sites listed for the eastern part of Macedonia.