Þyrill, (388 m) a basalt mountain with cliffs on three sides. Some rare kinds of zeolites are found there.
Above the farm of the same name there is a steep gully through the cliffs called Helguskarð (“Helga’s pass”) where the Sagas say Helga, daughter of a Norwegian Earl and mistress of the outlaw Hörður Grímkelsson, made her escape along with her two young sons.
She climbed up there after swimming with them from Geirshólmur after her lover had been hunted down and killed along with his band of outlaws.