Област Кюстендил (Kyustendil Province) in southwestern Bulgaria borders North Macedonia and the Republic of Serbia. The region features fertile valleys and canyons, separated by hillocks and mountains. The mountain ridges are named Milevska, Chudinska, and Zemenska mountains to the west, and Konyavska mountains to the west, and Osogovo, Vlahina and Rila mountains to the south. The Kyustendilsko kraishte (Kyustendil Cornerland) is drained towards Greece in the south by the Struma River and its tributaries.