Trou de Fer

The Trou de Fer ("Iron Hole") is a canyon on Reunion Island, off the coast of Madagascar in the Indian Ocean. The primary river flowing through the gorge, which is up to 300 m (1, 000 ft) deep, is the Bras de Caverne River, a tributary of the Rivière du Mât. The canyon has two distinct parts: a large crater, which is fed by six prominent waterfalls, and a narrow slot canyon at its outlet, which constitutes most of the canyon's length. The canyon starts at the waterfall of the Bras Mazerine stream and after some 1.4 – 1.8 km from the left side joins the main Bras de Caverne stream. The Bras de Caverne River enters the canyon with a waterfall about 200 m (660 ft) high. This drop is usually dry or has very little water, but between that and the next, 180-metre (590 ft) drop, springs feed the river, which drops over this then drops over a final 300-metre (1, 000 ft) undercut cliff into the Trou de Fer in a narrow plume of water. Directly to the left of this waterfall, another stream drops over the cliff, which is undercut to an extent that its lip has over 200 m (660 ft) of empty space between it and the canyon floor, of approximately the same height in two channels, and slams onto a ledge before emptying into the same pool as the Bras de Caverne waterfall. This waterfall is not as high, and has a smaller water flow. It is fed by several other falls streaming off the cliffs above it

Data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).