Vratnik Pass (Door pass) is a mountain pass at an elevation of 921m (3,021ft) above the sea level, located in the Sliven Province of Bulgaria.
Tucked away in the Balkan Mountains, the road to the summit is totally paved. It’s called Road 53. The road can be accessed year round but may be closed for short periods in winter when the weather is bad. The road is 23.2km (14.41 miles) long, running north-south from Stara Reka to Byala.