There is no shortage of travel modes routes into the kingdom, which occupies one of western Europe's transportation hubs. Virtually all international flights to Belgium arrive at Brussels Airport; the only exceptions are a handful of short-haul services that fly into Antwerp, and those of budget carrier Ryanair to its base at Charleroi -- employing marketing-speak, the airline calls the city's airport "Brussels-Charleroi."
In addition, there are ferry services from Britain to the ports of Zeebrugge and Ostend; high-speed trains from London, Paris, Amsterdam, and Cologne to Brussels (and some to Antwerp, Bruges, and Liège), along with "ordinary" international trains from around Europe; Eurolines bus service from many European cities; and multiple expressways/motorways from France, Germany, and Holland.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.