Lac Salé is one of the most photographed natural wonders of the Comoros: a saltwater crater lake set inside an old volcanic cone at the northern tip of Grande Comore, whose water shifts from turquoise to emerald green depending on the time of day and the light. Most striking of all is its setting: the crater opens almost onto the ocean, so from the rim you can see the impossibly coloured lake, the black lava around it and the blue of the Indian Ocean behind, all at once.
Also known as Lac Niamawi or Lac Gnamawi, the lake is tied to local legends. Tradition says there was once a village here whose people refused water to a holy man (or an old woman) who asked for it; as punishment, the volcano erupted and the lake swallowed the village. Its waters are said to have healing properties for the skin, and a curious superstition holds that it is impossible to throw a stone from the crater rim into the water, because of an optical illusion that tricks you about the distance.
This practical guide explains how to get to Lac Salé from Moroni, what to expect from the visit and which other sights in the north of the island to combine it with. It is a short but essential stop on any trip around Grande Comore, and one of those images (turquoise water, black rock and sea) that sum up the volcanic, little-known beauty of the Perfume Islands.
Lac Salé fills a volcanic crater in the north of Grande Comore, probably formed centuries ago by activity in the island's volcanic system. Its water is salty because of an underground connection with the Indian Ocean, from which it is separated only by a thin strip of lava. Legends surround it, about a cursed, buried village and about the healing powers of its waters. Its geological origin and folklore are covered in detail on our history page.
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Origins, formation and what the sources say.
The Lac Salé is, above all, a product of the volcanism that shaped the whole island of Grande Comore. It fills a crater — an old volcanic cone — at the northern tip of the island, in the Mitsamiouli region, near the village of Bangoi-Kouni. The crater is thought to have formed through the activity of the island's volcanic system, linked to the La Grille massif in the north and, more broadly, to the hotspot that built the archipelago up from the sea floor.
What makes the Lac Salé unique is its relationship with the ocean. The crater sits just a few metres from the Indian Ocean, separated from the sea by little more than a strip of volcanic rock. Its water is salty — hence the name — because there is an underground connection with the ocean, which seeps through the porous lava and keeps the lake at sea-level salinity. So, unlike most crater lakes in the world, which are freshwater, this is a rare saltwater lake of volcanic origin.
The intense colour of the water, ranging from turquoise to emerald green, comes from the combination of salinity, algae, dissolved minerals and light reflecting off the bottom. That shifting tone, together with the contrast against the black lava around the crater and the blue sea behind it, has made the Lac Salé one of the most recognisable and most photographed sights in the Comoros.
Like so many striking places in the archipelago, the Lac Salé — also known as Lac Niamawi or Lac Gnamawi — has its own legend, passed down from generation to generation. According to the most widespread version, where the lake lies today there was once a village called Niamawi. One day a holy man or an old woman — depending on who tells it — arrived in the village asking for water to drink, but every inhabitant scornfully refused.
As punishment for this lack of hospitality, a serious failing in Comorian and Islamic culture, the visitor cursed the village. Soon afterwards the volcano erupted and the waters rose to cover the entire village, and its inhabitants perished. The lake that now fills the crater would thus be the grave of a village punished for its greed. The story works as a moral parable about the duty to share water and to welcome the stranger.
Other popular beliefs surround the lake. Its waters are said to have healing properties, especially for certain skin conditions. And there's a curious superstition: it's said to be impossible to throw a stone from the crater rim into the water, because an optical illusion makes the distance look much shorter than it is, and the stone always falls short. Science and legend mingle in this corner of the Comorian north.
The Lac Salé belongs to a corner of Grande Comore with a lot of history: the Mitsamiouli region, at the northern tip of the island. This coast, made of black basalt lava flows that form coves, natural pools and beaches full of contrasts, was for centuries a point of contact with Indian Ocean trade and with the Swahili peoples of the African coast and Zanzibar.
Near the lake is the bay of Trou du Prophète ('the Prophet's hole'), a natural anchorage tied to legends and, according to some traditions, to the history of the sultans and seafarers who put in along these shores. Mitsamiouli and its neighbouring villages were part of the patchwork of sultanates and coastal communities that defined Grande Comore before and during the colonial period.
Today this northern strip is one of the most touristy areas of the island — within the modest scale of Comorian tourism — thanks to its beaches, its waters for snorkelling and diving, and, of course, the Lac Salé as its star natural attraction. Combining the lake with the beaches of Mitsamiouli and Chomoni lets you see, in a single day, much of the coastal beauty of northern Ngazidja.
The Lac Salé is an example of the natural wealth of the Comoros, a country whose tourism heritage rests mainly on its volcanic landscapes, its seabeds and its biodiversity. However, like many of those resources, the lake and its surroundings lack developed tourism infrastructure and formal protection and management mechanisms, which leaves them exposed to litter, erosion and the impact of unregulated tourism.
The challenge for the Comoros is to make the most of places like the Lac Salé to attract visitors — a potential source of income for a poor country — without degrading them. The recent inscription of the historic medinas on the UNESCO World Heritage List, in 2026, has put the archipelago on the cultural map; natural sites like this lake could benefit from that renewed interest if they are properly looked after.
For travellers, the Lac Salé remains an authentic, uncrowded place where you can take in a geological rarity — a saltwater crater lake perched above the sea — almost on your own. Seeing it today, with its turquoise water between the black lava and the ocean, is a glimpse at once into the geology, the legends and the quiet beauty of an archipelago that global tourism is only just beginning to discover.
