Þórsmörk and Landmannalaugur) has passed by this store, and maybe even dropped in for supplies or a bite to eat.
I wish I had the time to translate this entire article about this shop and the historic building it's in, but suffice to say the building is 164 years old and has always housed some type of business, starting with a restaurant in 1848 that unfortunately didn't thrive as planned. The store Vísir was established in 1915, and ownership has stayed in the same family: according to the article, as of 2003 the grandson of one of the original owners still ran the store.
I remember back when I was a little one staying with my Amma, Frú Ásta Beck, on Óðinsgata just up the hill, that I loved going to Vísir where, since 1959, the owners have prided themselves on always having a supply of fresh fruit. (Across the street, at the corner of Skólavörðurstígur and Laugavegur, in the half-basement where the café Kofinn is now,* was a butcher's shop with all sorts of cuts hanging in the window, a total novelty for a California-raised kid like me.)
*In the yellow building to the left in the third photo down in the post linked to above ; )