On the southern slopes of Geitahlíð in Krýsuvík is one of the most magnificent volcanic craters in the Reykjanes peninsula. It is called Stora-Eldborg for a distinction from smaller relatives down in the lava fields, Litla - Eldborg. Eldborg is by far the highest of five craters lying along a volcanic fissure in the slopes of Geitafell,
Stóra-Eldborg is a very formidable crater about 20 meters deep. It is a short distance from Suðurstrandavegur and therefore it is possible to scoop it up for a look at this beautiful natural construction. It is also interesting to stroll up the pass north of the crater, up the Geitahlíð itself to observe the volcano from above. The lava from Eldborg is around 7000-8000 years old.