Flight Sofia - Zonguldak prices from €182.35

Aegean Airlines is the largest airline in Greece, operating both domestic and international flights to over 150 destinations. Founded in 1987, the airline has grown to become a major player in the European aviation market, with a fleet of over 60 aircraft and a reputation for high-quality service. Aegean Airlines is a member of the Star Alliance, a global airline network that includes some of the world's largest carriers. The airline has won numerous awards for its customer service, including the Skytrax award for Best Regional Airline in Europe for nine consecutive years.

Air Serbia is the national airline of Serbia, headquartered in Belgrade. It was founded in 2013 as a successor to the former national carrier, Jat Airways. Air Serbia operates flights to over 50 destinations in Europe, the Middle East, and North America, with a fleet of modern Airbus aircraft. The airline offers a range of services to its passengers, including in-flight entertainment, Wi-Fi, and a loyalty program called Etihad Guest. Air Serbia is a member of the Etihad Airways Partners group, which includes several other airlines around the world. The airline has won several awards for its service and performance, including Best Airline in Eastern Europe at the World Airline Awards.

Austrian Airlines is the flag carrier airline of Austria, headquartered in Vienna. It operates scheduled services to over 130 destinations worldwide, including Europe, North America, Asia, and Africa. The airline is a member of the Star Alliance and has a fleet of over 80 aircraft, including Airbus A320, A321, A319, Boeing 767, and 777. Austrian Airlines offers a range of travel classes, including Economy, Premium Economy, and Business Class, with a focus on providing a high level of service and comfort to its passengers. The airline has won numerous awards for its customer service, including Best Airline Staff in Europe and Best Business Class Catering.

Bulgaria Air is the national flag carrier airline of Bulgaria, headquartered in Sofia. It operates scheduled flights to over 20 destinations in Europe, the Middle East, and Africa. The airline was founded in 2002 and has a fleet of 10 aircraft, including Airbus A319s and Embraer E190s. Bulgaria Air offers both economy and business class seating, as well as a frequent flyer program called Fly More. The airline has codeshare agreements with several other airlines, including Air France, KLM, and Alitalia. Bulgaria Air is a member of the International Air Transport Association (IATA) and the Association of European Airlines (AEA).

Corendon Airlines is a Turkish leisure airline that was founded in 2004. The airline operates flights to various destinations in Europe, Africa, and Asia, with a focus on holiday destinations. Corendon Airlines has a fleet of modern aircraft, including Boeing 737-800 and Airbus A320 planes. The airline offers a range of services to its passengers, including in-flight meals, entertainment, and comfortable seating. Corendon Airlines is committed to providing safe and reliable air travel, and has received numerous awards for its high standards of service. The airline is part of the Corendon Group, which also includes a tour operator and several hotels.

Hahn Air is a German airline that operates as a scheduled and charter carrier. However, it is best known for its role as a ticketing and distribution service provider for other airlines. Hahn Air has agreements with over 350 airlines worldwide, allowing them to sell their flights through Hahn Air's global distribution system (GDS). This enables travel agents to book flights on airlines that may not be available through traditional GDS systems. Hahn Air also offers its own branded flights to a limited number of destinations in Europe. The airline was founded in 1994 and is headquartered in Dreieich, Germany.

Lufthansa is a German airline and one of the largest airlines in Europe. It was founded in 1953 and operates flights to over 200 destinations worldwide. Lufthansa is a member of the Star Alliance, which is the world's largest airline alliance. The airline has a fleet of over 300 aircraft, including Airbus and Boeing planes. Lufthansa offers a range of services to its passengers, including in-flight entertainment, Wi-Fi, and a frequent flyer program called Miles & More. The airline is known for its high-quality service and has won numerous awards for its customer satisfaction and safety standards.

Turkish Airlines is the national flag carrier airline of Turkey, headquartered in Istanbul. It operates scheduled flights to over 300 destinations in Europe, Asia, Africa, and the Americas, making it one of the largest airlines in the world by number of destinations served. Turkish Airlines has won numerous awards for its service, including "Best Airline in Europe" six years in a row from 2011 to 2016. The airline operates a modern fleet of over 350 aircraft, including Airbus A320s, A330s, A340s, A350s, and Boeing 737s, 777s, and 787s. Turkish Airlines is a member of the Star Alliance, the world's largest airline alliance.

Wizz Air is a low-cost airline based in Hungary that operates flights to destinations across Europe, the Middle East, and North Africa. Founded in 2003, the airline has grown rapidly and now operates a fleet of over 100 aircraft, serving more than 150 destinations in 44 countries. Wizz Air is known for its no-frills approach to air travel, offering low fares and charging extra for additional services such as checked baggage and in-flight meals. The airline has a strong focus on efficiency and cost control, allowing it to offer some of the lowest fares in the industry.