La Palma has marked contrast between the forests of pines and laurels in the north and the arid, volcanic landscape in the south.  It is still in a stage of developing geologically characterized by rapid, volcanic growth.
In the past, the island grew so fast that it became unstable, and a major collapse of the Cumbre Nueva produce an enormous debris field beneath the sea which weighed almost as much as the part above sea-level.  The island emerged with the rising of a a submarine volcano, after which the volcanic activity formed the Caldera de Taburiente and New Ridge (Cumbre Nueva), with the Old Ridge (Cumbre Vieja) forming later.

This volcanic activity produced two very distinct geological zones; the northern massif and the volcanic, southern spine.  The first was built by eruptive episodes and constant erosion.  Its elliptical dome shape is due to the tectonic patterns running north-east-south-west, north-west-south-east and north-south.  The central spine is younger and still active.  Indeed, it is the site of all the historical eruptions on the island.  Its structure is simpler, but its geology is more varied as a result of more varied types of eruptions.   A string of volcanoes formed along the north-south tectonic line, making a backbone of relatively young and well preserved volcanic cones.  Runny lava spilled down their flanks until the mountain range formed the shape of a gabled roof.

As the volcanic activity has moved southwards over time, so the south of La Palma has a much starker landscape because nature hasn't had time to soften it. Volcanic eruptions happen fast, and change the landscape in days or even hours. In contrast, it takes a long time for erosion, plants, animals and people to alter it

The seven eruptions of the the Cumbre Vieja volcano within the last 500 years make La Palma one of the most volcanically active zones in the world.  The most recent eruption in Spain was here: that of Teneguía, in 1971, in the municipality of Fuencaliente.  This created a real paradise for volcano lovers and scientists.  In the north, the two-million-year-old lava flows and subsequent erosion have created a wild, rugged landscape.  It seems a world away from the motley landscape of cones and domes in the south.  In some places you can still touch warm rocks and the smell of sulphur permeates everything.  The eruptions of  Martín (1646),San Antonio 1677), El Charco (1712), San Juan (1949) and Teneguía have created vast lava fields which have scarcely been touched by time.  Plants, grasshoppers, beetles and lizards have been slowly colonizing this eerie landscape.