The Brussels Airport, also known as Zaventem, is the main airport in Belgium. It is well connected to the major cities in Europe. However, this airport is not located in Brussels, but the surrounding Flanders. It is the base of the national airline – Brussels Airlines.
You have Eurolines to get to Belgium from all over Europe. Apart from this, there are also international buses that have stopovers in Brussels north-station, Antwerpen, Liege and Leuven. There are also Flixbus and Ouibus at your service. You can even travel by car. All the major European highways such as E17, E19, E313, E314, E411, and E40 go through Belgium. The cheapest transport option to reach Belgium is by taxi or even carpool services.
Tourists do have the option of traveling to Belgium by sea. You have an overnight ferry to/from Zeebrugge from Hull in England. However, it is expensive.