Demir-Kapija is a place already mentioned in Classical times under the name of Stenae (Στεναί, "gorge" in Greek). Even earlier dates to the Paeonian era, a fortress for which remains on the mountain Ramniste on the foothills of the Demir Kapija settlement. The ruins are one of only 3 known Paeonian structures in Macedonia unearthed, and dating some 3000 years. In the Middle Ages Demir Kapija was known as a Slav settlement, under the name of Prosek, while today's name originates from the Turkish reign, meaning "The Iron Gate".