GR 128 is an almost 700 km. long hiking trail, called 'Vlaanderenroute’ (Flanders trail).
Flanders is interpreted in a very broad sense because the trail starts in Wissant (Witzand) near Cap Griz Nez (France) and first crosses the part of France that (in Flanders) is called 'French-Flanders'. Near the village of Kemmel the trail enters Belgium, and then continues in a straight west-east line through Flanders. Via Maastricht, the Voer region and the '3 countries spot' (Drielandenpunt), GR 128 ends it's journey in Aachen (Germany).
The complete trail is documented in 3 topoguides, published by the Flemish GR organisation.