Fjaðrárgljúfur (pronounced [ˈfjaːðraurˌkljuːvʏr̥]) is a canyon in south east Iceland which is up to 100 m deep and about 2 kilometers long, with the Fjaðrá river flowing through it. The canyon has steep walls and winding water. Its origins dates back to the cold periods of the Ice Age, about two million years ago. It is located near the Ring Road, not far from the village of Kirkjubæjarklaustur. The canyon was created by progressive erosion by flowing water from glaciers through the rocks and palagonite over millennia.Via the EarthPorn subreddit. I quite enjoyed this tongue-in-cheek clarification: "For those confused, it's pronounced 'flglhlhaldhslflr.'"