From northwest to southeast, its length is about 12 km, and its width is up to 10 km. It covers of a territory of 86 km2. To the northeast, east and southeast it reaches the valley of the river
Erma, and to the south its slopes descend steeply to the Tran valley, also known as
Znepole. To the north, northwest and west it extends to the valley of the river Blatanica (a left tributary of the Erma), and to the southwest through a saddle at an altitude of 1243 m, it is connected to
Miloslavska planina. Ruy is a typical massive, block-type mountain bounded by steep, faulted slopes. Its ridge is flat, at about 1600–1700 m above sea level. Its highest point is the eponymous summit of Ruy (1705.6 m), located in its western part, on the Bulgarian-Serbian border, at border pyramid No. 210. == Gallery ==