El Hierro, nicknamed Isla del Meridiano (the "Meridian Island"), is the second-smallest and farthest-south and -west of the Canary Islands (an Autonomous Community of Spain). At 268.51 square kilometres (103.67 sq mi), it is the second-smallest of the eight main islands of the Canaries.

El Hierro's size and geography support entirely endemic species including the critically endangered El Hierro giant lizard (Gallotia simonyi), for which there is a captive breeding programme, allowing its reintroduction.

In 2000, El Hierro was designated by UNESCO (United Nations Educational, Scientific and Cultural Organization) as a Biosphere Reserve, with 60% of its territory protected to preserve its natural and cultural diversity.

El Hierro is an island, formed late, about 1.2 million years ago after three successive eruptions, the island emerged from the ocean as a triangle of basaltic dykes topped with a volcanic cone more than 2,000 metres high. With continued activity resulting in the island expanding to have the largest number of volcanoes in the Canaries (over 500 cones, another 300 covered by more recent deposits), together with approximately 70 caves and volcanic galleries,

More Info: en.wikipedia.org