This island is situated about three km to the south of Island Bildsey and is very prominent from the town Stykkisholmur.  Its highest point lies about 22 m above sea level.

According the legend it was named Thoruholmi after the farmer of Daeldarkot in the Helgafell County caught a mermaid by hooking it under its belt. Her name was Thora.  He immediately fell in love with this beautiful, young girl, and they eventually agreed on her staying with him for three years before he would release her at the same spot.  They had one daughter, who later resided on the Island Ellidaey, where she usually sat on the edge of the cliffs and span wool into the sea.