Sahara Seamounts
The Sahara Seamounts are a group of seamounts which are located in the Atlantic Ocean between southwest of the island of El Hierro, part of the Canary Islands. A number of these seamounts are placed on the sea bed at depths of almost and some summits are just below sea level. An example of this is the seamount called Echo, which is also called the Endeavour Bank, where the summit is made up of a large plateau covering an area of , at depths of between and with the slopes dropping down to into the deep. The presence of  seismic lines around these seamounts show local unconformity or even sills which are quite high up among the sedimentary series and these features suggest that there was volcanic activity as late as at least the Cenozoic. These seamounts are home to a variety of marine life including deep-sea sharks (such as the Bluntnose sixgill shark "Hexanchus griseus", rays, wreckfish, conger eels, gadellas, escolars, roughies and other species of fish that occur in the extensive areas of sponges, gorgonians and corals. They contain the most southerly known beds of the glass sponges "Asconema setubalense". Images taken from an ROV show  that these seamounts have rocky and sandy sea beds which are volcanic in origin and that they contain numerous caves, overhangs and cracks which shelter a variety of animals. These seamounts may be rich in certain minerals and the crust is rich in cobalt, as sampling at the Tropic Seamount, one of the Sahara Seamounts, showed.