| Banja Stijena | |
| Other Name: | Mračna pećina |
| Alt Name: | Banj Stijena, Ban Stijena (referring to medieval title) |
| Location: | Prača, Bosnia and Herzegovina |
| Map: | Bosnia |
| Coordinates: | 43.7753°N 18.8897°W |
| Relief: | yes |
| Mark: | Cave symbol.svg |
| Mark Size: | 15px |
| Label: | Banja Stijena |
| Label Position: | left |
| Discovery: | early 20th century |
| Geology: | Karst |
Banja Stijena, also Banj Stijena, Ban Stijena (referring to medieval title), or Mračna Pećina, as locally known, is a cave in Bosnia and Herzegovina located in the canyon of the river Prača. The cave has an extensive channel system about 2,000 meters long. It is rich in various types of cave features. It was first mentioned in the early 20th century when constructing a railway through the canyon. Access to the cave was mined during the Bosnian War.[1]
Banja Stijena cave is a special geological reserve.