Geirmund's Hall is a Nordic ruin and crypt on a small island in Lake Geir just to the east of Ivarstead. This is where the Dragonborn can find Sigdis Gauldurson.
Inside the crypt are many mushrooms, a dead adventurer with a copy of Lost Legends, Geirmund's Epitaph, an arcane enchanter and a copy of the skill book Words and Philosophy. It is also one of the few locations with either pearls or small pearls.