Passage: During the Ice Age (up to 10,000 years ago) a large glacier covered parts of the city area, reaching as far out as Álftanes. Other parts of the city area were covered by sea water. In the warm periods and at the end of the Ice Age, some hills like Öskjuhlíð were islands. The former sea level is indicated by sediments (with clams) reaching (at Öskjuhlíð, for example) as far as 43 m (141 ft) above the current sea level. The hills of Öskjuhlíð and Skólavörðuholt appear to be the remains of former shield volcanoes which were active during the warm periods of the Ice Age. After the Ice Age, the land rose as the heavy load of the glaciers fell away, and began to look as it does today.

Question: What was the name of the hill that was actually an island as well?
Öskjuhlíð