Misilyah is situated in a small plain in the foothills of Jabal Faḳu'ah, or Mount Gilboa. The plain, Marj al-Gharaḳ, also spelled Merj el-Ghǔrǔk, which lacks any natural drainage, was described at the beginning of the 20th century as transforming into a large swamp during the rainy season, only to dry up in summer, when the resulting field was cultivated with grain.