An Sgùrr is the highest hill on the Inner Hebridean island of Eigg, Lochaber, Highland, Scotland. It was formed 58.72 ± 0.07 million years ago; the result of one of the last eruptions of a volcano, the core of which now forms the Isle of Rùm. Thick viscous pitchstone lava of rhyodacitic composition flowed out, filling a river valley.