This is a point to point challenge in which the runner hits five Blackstairs summits, including Mt Leinster. The runner chooses their route between each summit. 

The Giants of the 3 Nations takes in 4 of the highest peaks in Andorra, France and Catalonia and is considered one of the more difficult trails in this area of the Pyrenees. The route summits the Comapedrosa peak (2,942m), Pica d'Estats (3,143m), Tristaina peak (2,878m) and the Medacorba (2,914m) which lies at the point Andorra, France and Spain meet.

This route starts at Wantastiquet mt in Hindsdale and traverses to mt Monadnock then continuing on to mt Sunapee.

It combines the Wantastiquet-Monadnock Trail with the Monadnock-Sunapee Greenway Trail, both already FKT routes.