Fjaðrárgljúfur is a magnificent  canyon, about 100 meters (330 ft) deep and about two kilometres (1.2 miles) long. The canyon has sheer walls, and is somewhat serpentine and narrow. The bedrock in Fjaðrárgljúfur is mostly palagonite from cold periods of the Ice Age and is thought to be about two million years old.

There is a walking route along the eastern edge, and it is possible to walk up through the canyon, though then one must wade across the river few times, but it´s not deep

For those not scared of heights the view from one of those rock pillars down the canyon is majestic. You can see how tiny the two people standing there are compared to the surroundings. For those traveling the Icelandic south coast, don´t miss this