The plain relief in the north parts gradually turns to low-mountain - here is included a part of the Dervent Elevations, which are very similar to The Stranja Mountain in their geographical characteristics. A conditional boundary between them is the flat saddle from which the Popovska River springs. The state boundary with Turkey passes along their crest.
The village of Stefan Karadjovo famous for its healing mineral springs is just a few kilometers away from village of Boyanovo.