Why You Can't Swim in Lake Nero, and What Centuries of Silt on the Bottom Have to Do With It

From the embankment in Rostov Veliky, Nero looks like a proper large lake: the far shore is several kilometres away, and the white walls of the kremlin and monasteries line the water. But locals advise against going into it. Beneath a thin layer of water lie metres of silt that has been building up for thousands of years.

In summer, tourists who come to Rostov on the Golden Ring route of historic towns around Moscow often ask locals the same question: where's the beach? The lake is huge, it's hot, the water is right there, yet nobody is swimming. The answer comes as a surprise: swimming in Nero isn't the done thing, and on the town embankment it's officially banned. The reason is that Nero has an unusually thick layer of silt: there's little water in the lake, but an awful lot of lake bed.

A Big Lake With Hardly Any Water

In terms of area, Nero is impressive: about 58 km², more than 13 km long and about 8 km wide. It's one of the largest lakes in the Yaroslavl Region.

The depth is another matter. According to the Rostov Kremlin museum reserve, over most of the lake it's about 1.5 metres deep, and only in the north-east does the bottom drop to just over 3 metres.

For a lake of this size, that's very shallow.

What Lies on the Bottom

Beneath this thin layer of water lies Nero's defining feature: sapropel. These are sediments formed from the remains of algae, plants, microorganisms and mineral particles. Layer by layer, they settle on the bottom and, over thousands of years, turn into a soft, dark mass. Sapropel is usually 95–98% water, so it's essentially a sticky ooze rather than a solid lake bed.

There's a great deal of this silt in Nero. According to the museum reserve, it's about 5 metres thick on average, and more than 20 metres in places. By a rough estimate, that's around 250–300 million m³ of sediment. If you estimate the volume of water in the same way, from the lake's area and depth, Nero turns out to contain several times more silt than water. In other words, Nero is slowly but surely filling up with its own silt.

Why the Silt Makes Swimming Dangerous

The most obvious problem is the bottom. If you get into Nero, you're standing not on sand but on soft silt that your feet sink into. Walking on a bed like that is hard work, and getting out of the water is even harder, especially if you panic.

Rostov's tourist guides say it plainly: the lake is shallow, with a silty bottom, and there are no convenient or safe places to swim.

The second problem is water quality. A shallow lake warms up quickly, and sapropel is rich in organic matter and phosphorus. In summer, this water is the perfect environment for algae and microorganisms to multiply rapidly. For years, Nero also suffered from wastewater: Rostov's worn-out sewer system regularly broke down, and residents repeatedly complained about discharges into the lake.

In August 2026, the regional office of Rospotrebnadzor, Russia's consumer health watchdog, reported that the water at swimming spots in six districts of the region, including the Rostov district, as well as in Yaroslavl itself, failed to meet sanitary requirements. Local authorities were ordered to put up no-swimming signs.

Where Exactly Swimming Is Banned

Sections of the Nero embankment in Rostov are on the official list of places in the Yaroslavl Region where swimming is prohibited, and these are the main spots in town where you can get down to the water.

There are no official beaches on Nero. If you see people swimming from the shore, it doesn't mean the water is safe: they're most likely locals swimming at their own risk.

Why the Lake Can't Be Cleaned Up

People have been trying to clean up Nero for a long time, so far without success. In 2015, 300 million roubles was allocated from the federal budget for the first stage of the work, mainly to deepen the mouths of the rivers flowing into the lake and repair the storm drains.

According to estimates at the time, restoring the whole lake would have cost almost three times as much. But the work was halted after inspections: some of it had been done only on paper, the contractor had embezzled the money, and the head of the contracting company was given a prison sentence.

There's a technical difficulty too. The lake's level is regulated by a dam on the Veksa river, and campaigners blame it for disrupting the natural water exchange: in their view, the level has been set without regard for the lake's needs. The soft ground also complicates work on the shore: if it's cleared carelessly, it can start to slide.

The good news is that work has begun on tackling the main source of pollution. In 2025, a new wastewater treatment plant opened in Rostov Veliky, and as of summer 2026, repairs to the sewer network near the lake were 90% complete.

And on September 7, 2026, reconstruction of the embankment began: the stretch, more than 3 km long, will cost just over 2 billion roubles (1.5 billion of it from the federal budget), and the work is due to be completed by 2028.

What to Do on Nero Instead of Swimming

Nero is best enjoyed not in the water but on it. In summer, pleasure boats ply the lake, offering views of the Rostov Kremlin and the Spaso-Yakovlevsky Monastery that you can't get from the shore. For something more active, there are instructor-led SUP outings, rowing boats and pedal boats. Beginners are better off joining organised trips: falling off a board in a shallow lake with a silty bottom is not a pleasant experience.

The lake is a popular spot for fishing, with pike, zander, bream and roach. And the quintessential Rostov experience is a sunset on the embankment, when the domes and silhouettes of the monasteries stand out against the evening sky.

If it's hot and you're desperate for a swim, it's best to check the list of official beaches in the Yaroslavl Region in advance: in 2026, there were 42. But even there, it's worth checking the latest test results, as the list of places fit for swimming changes over the summer.