The Interland Cup is England’s only international competition outside the British Isles. England competes annually in this five-cornered match against two Belgian teams (Flemish and French speaking), the Netherlands, and the French Ligue des Hauts de France de Course d’Orientation (LHFCO) . The competition is truly a team effort spanning age groups from W and M14 to W and M60+: 42 team members in all. The Rules and Guidance for the competition are here:
Interland Rules and Guidelines

2019
Interland will take place in France on 10 March in the Val Joly departmental park (59132 Eppe-Sauvage), near the Belgian border.”