Salda Gölü (Lake Salda)

The Lake That Mirrors Mars

Show someone a photograph of Salda Gölü without naming it, and they will guess wrong. 

The Maldives, usually. Sometimes the Caribbean. White shore, water shifting from milky turquoise to deep blue, a brightness that looks borrowed from a travel brochure.

The guesses miss by thousands of kilometres. Salda lies in the hills of Burdur, in southwestern Türkiye, at nearly 1,200 metres above sea level, surrounded by pine forest and dry rock. The tourism industry has made peace with the confusion and calls it Türkiye'nin Maldivleri, the Maldives of Türkiye.

The strangest comparison turned out to be the most accurate one.

When NASA's Perseverance rover landed in Jezero Crater on Mars in February 2021, it began searching the bed of a lake that dried up billions of years ago. To understand what the rover might find, scientists had been studying a living lake on Earth whose shoreline carries minerals closely comparable to the carbonates detected at Jezero. That lake was Salda. A quiet basin in Burdur became a field guide to another planet.

And the white beach that fools everyone is not ordinary sand.

What It Looks Like

The shore of Salda is dominated by hydromagnesite, a hydrated magnesium carbonate. The slopes around the lake are ultramafic rock, material that once belonged to the ocean floor, and water moving through it feeds the lake an unusual chemistry: highly alkaline, rich in magnesium.

In the shallows, life takes over. Cyanobacteria, among the oldest organisms on Earth, help the mineral settle into layered structures called microbialites. These are rocks built with the participation of living things, relatives of the stromatolites that record the first chapters of life on this planet. Waves slowly break the structures down, and their fragments wash up as the famous white shore.

So the beach is part fossil, part living geology. The lake has not finished making it. The white grains are the remains of microorganisms that lived thousands of years ago, mixed with the work of colonies still alive in the water today. Stand on the shore of Salda and you are standing on several thousand years of microscopic labour.

The colour comes from depth. Salda is a closed basin: streams flow in, nothing flows out, and the bottom falls to about 184 metres, which makes it one of the deepest lakes in Türkiye. Over white mineral ground the water glows pale turquoise. Where the bed drops away, it darkens to ink. The bands of colour are a depth chart you can read with the naked eye.

The drop is not gradual everywhere. In places the bottom falls away within a step or two. The villagers have known this for generations.

Where It Is

Burdur province, the inner southwest. The lake sits in the Yeşilova district, about four kilometres from the town. Burdur city is roughly 60 kilometres away, Denizli about 100, Antalya about 160. Close enough to Pamukkale that travellers often see both in a single trip: one white wonder made by hot springs, another made by microbes.

This is the Göller Yöresi, the Lakes Region, where tectonic movement has folded the land into basins that hold water. Salda's own basin began forming roughly five million years ago, and the process is still active. The lake covers about 44 square kilometres, small enough to see across, deep enough to hide everything below its first few metres.

Several villages sit within the protected basin, and one of them is called Salda. The lake carries the village's name. What the name Salda itself means, no one can say with certainty. It keeps its bottom hidden, like the lake.

Stories from the Shore

The people of Salda village had their own science long before the geologists arrived.

They hold that the water heals, especially the skin: itching, rashes, the kinds of complaints that send people wading into the shallows and coating themselves in white mud. In spring, villagers describe a bluish haze gathering over the water, and breathing it is believed to ease shortness of breath. The word they use for that haze is mavimtırak, bluish.

Above all, the village holds one rule: water sources must never be made dirty. Researchers who studied these customs recognise in them the trace of pre-Islamic Turkic belief, in which springs and lakes were treated as presences, almost as persons. At a nearby spot called Çatal Armut, sick children were once bathed in waters considered healing, and people tied strips of cloth to the pear tree there while making a wish. The custom is called çaput bağlamak, tying a rag. Wish trees like that one still stand all over Anatolia, their branches heavy with faded cloth.

Then there is the darker story. Around Salda you will hear that the lake is dipsiz, bottomless, and that it pulls swimmers down. Some blame the clay bottom, which can grip like a marsh. Others say flatly that the lake takes people. Calmer voices point out that most victims simply could not swim, and that the bottom can drop away within a single step.

The legend says the lake takes people. The depth chart says it can. Folklore and bathymetry, for once, give the same advice: stay near the shore.

From Salda to Jezero Crater

The Mars story is older than the rover, and it did not begin with NASA.

In 1999, a team led by the geologist Michael Russell published a paper in the Journal of the Geological Society with a remarkable title: "Search for signs of ancient life on Mars: expectations from hydromagnesite microbialites, Salda Lake, Turkey". The argument was simple and twenty years early. If a Martian lake ever held life, its traces might be preserved the way Salda's microbialites preserve the work of their microbes. Nobody yet knew where on Mars to look.

The answer came from orbit. An instrument aboard NASA's Mars Reconnaissance Orbiter detected magnesium carbonates along the margins of Jezero Crater, with spectral signals closely resembling hydrated magnesium carbonates like hydromagnesite, the mineral that dominates Salda's shore. In 2018, NASA chose Jezero as the landing site for its next rover. A paper written about a lake in Burdur had, in effect, predicted the address.

So the scientists came to Burdur. In 2019, the planetary scientist Briony Horgan of Purdue University and research teams from Istanbul Technical University worked along Salda's shoreline, mapping where the carbonates form and what survives inside them. After the landing, Prof. Dr. Nurgül Balcı of Istanbul Technical University carried the research further with American colleagues, using Salda to ask whether Mars once held life, and whether something might still persist deep underground there. Her team has mapped six distinct microbialite zones in the lake, with structures shaped like linked columns and cauliflower heads, growing from the shallows down to about fifteen metres.

The logic is simple. Perseverance is collecting rock from Jezero's ancient shoreline, where the carbonates are. On Earth, lake carbonates are among the best keepers of biological traces. Salda shows what such deposits look like while they are alive, so that scientists will recognise what the Martian samples mean when they are finally opened.

The lake has since been recognised internationally as a geological heritage site because of this rare Mars connection.

Jezero is what Salda would become after three billion years without water. The villagers, who never heard of Jezero, always insisted their water must be kept pure. The scientists arrived with spectrometers and reached a similar conclusion. The lake holds knowledge, and it is worth protecting.

The Words Inside the Name

Salda Gölü follows a pattern stamped across the entire Turkish map. Göl means lake. The ending -ü is a possessive suffix. Together they form a belirtisiz isim tamlaması, an indefinite noun compound: Salda Gölü, Van Gölü, Tuz Gölü. The first word names, the second carries the suffix. Learn the pattern once and half the map opens up.

Sometimes the map translates itself. The town beside the lake is Yeşilova: yeşil is green, ova is plain. The green plain. Nobody thinks of it as a description anymore, but the description is sitting right there, the way Pamukkale hides cotton and a castle inside one word.

The lake's folklore happens to teach a perfect pair of suffixes. Locals call the water şifalı and the lake dipsiz. Şifa is healing; add -lı and you get "with healing". Dip is the bottom; add -siz and you get "without a bottom". The two suffixes are mirror images, one gives and the other takes away. Şekerli çay, tea with sugar. Şekersiz çay, tea without. At Salda the pair occurs in the wild: suyu şifalı, dibi yok. The water heals, and the bottom is missing.

Now the haze. Villagers describe the spring mist over the water as mavimtırak, bluish. The suffix -imtırak softens a colour, makes it approximate: mavimtırak, bluish; yeşilimtırak, greenish; ekşimtırak, sourish. Its gentler cousin -imsi does the same work: mavimsi, yeşilimsi. Turkish has whole suffixes dedicated to almost. For a lake whose colour refuses to settle, the village chose exactly the right word.

When the colour does settle, Turkish reaches for pekiştirme, intensification: beyaz becomes bembeyaz, pure white, and mavi becomes masmavi, deep blue. On Salda's shore you need both at once. Kumlar bembeyaz, su masmavi.

And one proverb belongs here more than anywhere. Damlaya damlaya göl olur. Drop by drop, a lake forms. Turkish uses it as English uses "little strokes fell great oaks": patience accumulates. At Salda the proverb is nearly a geological report. A closed basin filled drop by drop over five million years, a white shore assembled grain by grain by creatures too small to see.

Keeping It Blue

Salda's beauty became its main danger. When photographs of the white shore spread online, visitors multiplied, and so did the pressure on a surface that takes centuries to grow and a footstep to crush. People walked on living microbialites. They bottled the white sediment as souvenirs.

The protections came in layers. The lake and its surroundings have been a first-degree natural protected site since 1989. In March 2019, Salda was declared a Özel Çevre Koruma Bölgesi, a Special Environmental Protection Area, by presidential decision, covering 295 square kilometres, roughly seven times the surface of the lake itself. The most fragile section, the White Islands (Beyaz Adalar), is closed to swimming. Removing sand or mud from the lake is forbidden. Even smoking on the beaches is banned.

The rules were tested almost immediately. In 2020, construction machinery working on a state landscaping project damaged the beach, and white sediment was excavated and trucked five kilometres to another part of the shore, prompting an official investigation. 

Scientists have warned that pollution is darkening the hydromagnesite in places, and the water level has dropped three to four metres over the last twenty years and is still falling, part of the drought pressing on lakes across Türkiye.

The village always had one rule: do not dirty the water. The state now says the same thing in the language of decrees and protection zones. Both are trying to prevent the one outcome everyone can now picture, because a photograph of it already exists. It was taken on Mars.