If you are interested in Bulgarian history, especially its communist history and the cold wars it fought, this museum located in the city's airport will surely like it. It is an open-air museum that displays some of the weapons and warplanes that Bulgaria resisted and fought in during the wars. And this museum will definitely take you to another world. The city was not as quiet as it is now, as it was the headquarters of the Bulgarian Air Force and fought many wars and lost many lives. There are several guides in the museum who will explain to you about all the exhibits and their history.