Þóristindur is located NE of Hekla in the Veiðivötn area. The mountain is of volcanic origin, it is a "móbergshryggur" (tuff ridge) which is indicative of a sub-glacial eruption. Climbed on 4-Mar-2006.
View from the NNE, an "end-on" view. This is the ascent route recommended in the book "Icelandic Mountains, Hiking Routes to 151 Peaks" but we didn't fancy our chances on those icy rock outcrops near the top!