La Cueva de los Verdes
La Cueva de los Verdes © tete_ct
In the northern part of Lanzarote, close to the Monte de la Corona volcano, is a spectacular system of underground grottos known as La Cueva de los Verdes. This is one of the largest volcanic galleries in the world, at just over four miles (6km) long, formed approximately five thousand years ago in a prehistoric eruption when a massive stream of lava boiled down to the sea, hardening around the spaces inflated by gases. Where the tunnel enters the sea there is an underwater section called the Tunnel of Atlantis. More than a mile (2km) of these grottos is accessible to visitors, and lighting effects have been added to accentuate the contours and colours of the weird shapes resulting from the lava flows.