Fiľakovo town is situated in the orographic unit Cerová vrchovina upland, the subunit Fiľakovo Trough. The highest mount of Cerová vrchovina upland is Karanč (725 m a.s.l), which occurs on the Slovak-Hungarian boundary, 12 km southwesterly from the Fiľakovo town. The range of elevations above sea level in Fiľakovo cadastre is 185 – 350 m a.s.l. The divide contour line betwen Ipel and Tisa rivers runs through Cerová vrchovina upland (altitudes Medvedia výšina /659 m a.s.l./, Pohanský hrad /578 m a.s.l./, Veľký Bučeň /514 m a. s. l./). Through the cadastre from south to north flows Belina stream belonging to Ipeľ river-basin. The mean annual precipitation is about 600 mm in the area. The mean annual air temperature is 8,4 - 9 °C, on January -3,8 - -4 °C, on July 20 - 21 °C. From geological point of view the area is built by neogene sandstones and vulcanites. Among of soils dominate brown soils, another soil types occur in minor rate, fluvial soils occur in valleys. The relief of the Cerová vrchovina upland has inverse character - it means - in erosion process the lava flows filling valleys turned to shoulders and original shoulders changed to the valleys. A sharp relief segmentation is the characteristic feature of the area.
The central part of Cerová vrchovina upland with area 16 771 ha is a part of Protected Landscape Area Cerová vrchovina, which is closest to Fiľakovo 4 km southeasterly from the town. The castle hill Fiľakovo is a point part of Protected Landscape Area (PLA) Cerová vrchovina. There are no small protected areas with higher (4., 5.) protection level in Fiľakovo cadastre. To the Fiľakovo nearest small protected areas belong Nature Monument Belinské skaly (Belina cadastre), Nature Monument Čakanovský profil (Čakanovce cadastre), Nature reserve Kerčík (Šávoľ cadastre), National Nature Reserve Pohanský hrad (Šurice, Stará Bašta cadastres), National Nature Reserve Šomoška (Šiatorská Bukovinka cadastre), Nature Monument Soví hrad (Šurice cadastre). Since February 2008 the Territory of PLA Cerová vrchovina belongs to NATURA 2000 system as Special Protected area Cerová vrchovina - Porimavie. From natural science point of view most valuable and well-preserved biotopes of Cerová vrchovina upland with area approx. 3.500 ha are another part of NATURA 2000 system - Special Area of Conservation.