Ver Cuevana 3. For canyoning enthusiasts, the Trou de Fer on Reunion Island is a must-see, and not just for the faint-hearted. The first complete descent of the canyon, with a 1,000-meter drop, was made by Thierry Krattinger, Stéphane Girard, and Jean-Claude Dobrilla in 1990. Filming took place in very difficult conditions: an aquatic atmosphere, a dramatic void, and mediocre rock in the 300-meter waterfall. The documentary Trou de Fer was selected for competition at the Trento Film Festival in 1992.