Şırnak is a town in .
East towards Hakkari
This is, by far, the most militarized road in Turkey and there's a scarcity of vehicles. However the hitchhiker who perseveres and brings with him/her a fair amount of time and a whole lote of patience will be generously rewarded as this is (in hitchhiker Theo's modest opinion) the most scenic road in Turkey.
From the city centre you simply ask people for directions to Hakkari Yolu (there are almost no signs). Once you get to the Jandarma base you'll be able to see where the road from the city intersects where the highway which dont pass through Sirnak. There's a great hitchhiking spot about 50 meter after the intersection. Either walk the 1 km there or try to hitch a ride.