The route through the Nisava valley has been a major gateway to Europe from Asia since ancient time .The route pass through the valleys of Morava and Marista before it reaches Istanbul . The Belgrade- Sofia- Istanbul Highway and a railway line also follow the same route.
The Nisava valley , which sits in between Asia and Europe , is a major natural gateway to to Europe from Asia , and then it passes through the valleys of Morave and Maritsa before it reaches Istanbul