İslahiye is a municipality and district of Gaziantep Province, Turkey. Its area is 865 km, and its population is 67,650. It is a railway border cro…İslahiye is a municipality and district of Gaziantep Province, Turkey. Its area is 865 km, and its population is 67,650. It is a railway border crossing into Syria. Near İslahiye is the site of ancient Nicopolis.