[5] It is about 25 km2 (9.7 sq mi)[4] and includes the Reykjanes volcanic system that extends in a linear fashion up its centre continuing to the north-east as the hill of Sýrfell at 93 m (305 ft) high.

[7] Valahnúkamöl is its south western cliff coast leading to Reykjanestá, the most south-western cape of the area.

The basaltic low relief lava shields of the Reykjanes volcanic system are typically more than 4500 years old, but towards the south there are more recent eruptive fissures,[8] with crater rows, tindars and hyaloclastite hills as well as parts of tuff cones near the south-west shoreline.

They are separated by about 2 km (1.2 mi), and their western parts have been active in the last three eruptive periods of the Reykjanes area.

[19] On the Reykjanes Peninsula itself, the system has had its geothermal potential exploited, producing up to 176 MW of power.

[3] Most of the Reykjanes area is at risk of disruption from future eruptions and susceptibility maps have been published.