Demirkapı is a village in Şirvan District, in Siirt Province, Türkiye. Demirkapı lies at 1,358 m above sea level, in the Southeastern Taurus mountains. It has 110 inhabitants. The nearest city is Siirt, 21 km to the southwest. Among the landmarks around are Tomb of İsmail Fakirullah (15.9 km) and Alkumru Dam (13.5 km).