The Red Sea is a tough place to call home. Largely land-locked, more like a lake than a sea, it has a higher salinity and is warmer than most other seas around the world. And yet, its coral reefs are thriving, seemingly immune to the changing climate that wreaks havoc elsewhere. These corals, and their DNA, might be the last hope for one of the most important ecosystems on Earth.

The unique creatures that inhabit the coasts and islands of the Red Sea are as diverse and beautiful as the habitats born from a giant gash in the Earth’s crust that appeared 130 million years ago.

Thanks to its geography, the Red Sea is a place of extremes. No rivers feed into it from the surrounding desert and little rain falls here. As a result, the water has significantly higher salinity than the neighboring Indian Ocean. In addition, the sea is incredibly warm, even in its darkest depths. 6,000 feet below the surface, the water measures a record 75 degrees Fahrenheit.

In winter a huge shiver of whale sharks slowly meanders towards the Gulf of Tadjoura – the narrow southern entrance to the Red Sea. They come in their hundreds, though these behemoths typically prefer a life of solitude. These are juveniles, already stretching more than 12 feet. Their seasonal congregation remains a mystery.

At the mouth of the Red Sea, the isolated island of Socotra—a UNESCO world heritage site—is known as “the most alien-looking place on Earth.” Cut off from the rest of the world, unique wildlife has evolved.

Written and directed by Harald Pokieser, Photography: Nuno Sá, Massimo Verde, Sven Bender, Christian Stolz, Sound recording: Magdalena Pokieser, Tim Teichmann, Valentin Blüml

A co-production of ORF, ORF-Enterprise, ARTE, NDR Doclights and National Geographic International.