At the foot of the Corona Volcano, the subsoil of Lanzarote is riddled with underground galleries formed by lava streams. Upon contact with the air, the surface of the lava streams cools and hardens into a dense layer of basalt, underneath which molten magma continues to circulate as if flowing through a system of pipes. There is now a 2km network of these tunnels, which run along various levels. The site, which comes under the protection of the Fundación César Manrique, is illuminated to beautiful effect. Auditorium.