Sofia Airport is the main international airport of Bulgaria with one large runway of 11,811ft (3.6km). It is located 8.5km from Sofia city-centre. The airport has customs clearance and five Fixed Based Operators with handling agents that operate 24 hours a day. Slots are required at this airport. The Vrazhdebna Air Base of the Bulgarian Air Force is also located at the airport. There is one VIP terminal located in Terminal 1 with its own private entrance.