The river is a left tributary of Struma river. It is formed by the rivers Dolenska and Sugarevska, flowing one in another between the village of Sugarevo and the town of Melnik. Melnishka river is one of the reasons for the formation of the popular Melnishki pyramids. Even nowadays, the river and the rain continue to form new pyramids. It flows through the center of the town of Melnik and often dries up in the summer.