Skógafoss (pronounced [ˈskouː(ɣ)aˌfɔsː] ) is a waterfall on the Skógá River in the south of Iceland at the cliff marking the former coastline. After the coastline had receded (it is now at a distance of about 5 kilometres (3 miles) from Skógar), the former sea cliffs remained, parallel to the coast over hundreds of kilometres, creating together with some mountains a clear border between the coastal lowlands and the Highlands of Iceland.
Herðubreið (Icelandic pronunciation: [ˈhɛrðʏˌpreiːθ] , broad-shouldered) is a tuya in the northern part of Vatnajökull National Park, Iceland. It is situated in the Highlands of Iceland at the east side of the Ódáðahraun ([ˈouːˌtauːðaˌr̥œyːn]) desert and close to Askja volcano. The desert is a large lava field originating from eruptions of Trölladyngja and other shield volcanoes in the area. Herðubreið was formed beneath the ice sheet that covered Iceland during the last glacial period.
A volcanic desert is an area largely or completely devoid of vegetation because of volcanic activity. The term is usually applied to larger areas such as the Highlands of Iceland, the Rangipo Desert in New Zealand or Cordón Caulle in Chile. Occasionally though, it is used for relatively small regions such as the Kaʻū Desert on the island of Hawaiʻi.
Volcanic deserts may have enough precipitation to sustain vegetation, but due to repeated covering of tephra and acid rain after eruptions and high percolation and infiltration rates of water, vegetation is scarce. In addition to this volcanic desert shows often poor or little soil formation due to slow chemical weathering caused by cold climate or coarse tephra. This is how the Plaine des Sables, on the island of Réunion, can find itself close to the Commerson Crater, a place which holds several world records of rainfall.