Arrival by air: http://www.brusselsairport.be/
Belgium has one international airport (Brussels International Airport Zaventem). From there, take the train towards Blankenberge:https://www.belgiantrain.be/en/travel-info/current/current-departure-times
The train ride from Brussels Airport (Zaventem) to Blankenberge lasts about 2 hours, with a transfer in Brussels Midi (Brussel Zuid).
Arrival by train: take the train from Brussels Midi (Brussel Zuid) to Blankenberge: https://www.belgiantrain.be/en/travel-info/current/current-departure-times
From Blankenberge railway station, take the coast tram towards Knokke, and get out at “Corsendonk de Duinse Polders”: http://www.delijn.be. There is a tram every 10-15 minutes.