How much elevation gain (D+) on the Diagonale des Fous?

Tackling the Diagonale des Fous means taking on the island of Réunion—here are the key figures:

Distance: ~180 km

Elevation gain (D+): 10,200 m

Elevation loss (D-): 10,200 m

Highest point: ~2,411 m

Forget about the time completely: on a route like this, the one and only goal is to manage to cross the finish line.