Everything you need to know about Estonian bogs

Bogs have been an important part of the local ecosystem for thousands of years. Here's an in-depth look at Estonia's oldest landscape.

Romet Vaino

Nature guide, photographer, and writer

Romet Vaino is a tour guide, photographer, and writer who has compiled a comprehensive guide to Estonian mires, bogs, and wetlands for any visitor dreaming of hiking there. He'll explain what a bog is, what the story behind it is, when to go there, and which bogs to go to.

Estonian bogs have undergone a major transformation in recent years.

They were once seen as a horrific place, but are now considered one of the country's most beloved landscapes. Our bogs are a bucket list attraction for every visitor willing to venture into the Estonian countryside.

Photo author: Priidu Saart, Visit Estonia

What is a bog?

Bogs are the oldest organic landscapes in Estonia, dating back at least 10,000 years.

The first bogs started to emerge here right after the last Ice Age. As the 1 km-thick glacier ice sheet receded towards the North Pole, the meltwater, as a byproduct, collected in depressions previously created by the glacier ice. Over the next thousands of years, plants grew and died in those shallow, oxygen-deprived lakes. As a result, the dead plant material didn't decompose but instead formed ever-lasting peat/turf and made the water acidic. Every year, one layer of partially decomposed organic material accumulates underneath the mossy surface of the bog, and this effect has taken place since the very beginning!

In Estonian bogs, the pace at which the peat accumulates is roughly 1 mm annually. In most Estonian bogs, the peat layer averages 5-7 meters thick, corresponding to about 5,000-7,000 years of age.

Over the course of thousands of years, this landscape has gone through a series of transformations.

At the very beginning, this peat accumulation has no significant effect on plants – the peat layer is just too thin, and the flora can reach the nutrient-rich groundwater. After a few millennia, the peat layer thickens and filters out more demanding plants. The landscape changes. Birch trees give way, and pines slowly start to take over. A bog in this middle stage is called a transitional mire.

Later, the peat layer becomes so thick that only the toughest plants survive. The third stage is called a bog or raised bog. Here you can see many bog pools or lakes within this huge organic sponge. The landscape is entirely independent, meaning the plants don't have access to nutrient-rich groundwater; all they have is rainwater. Bogs are like sponges that can store huge amounts of water, mainly because sphagnum moss, also known as the "bog builder plant," is able to absorb almost 20 times its body mass. So in some ways, bogs are also giant reservoirs.

Facts about Estonian bogs

The oldest bogs in Estonia are estimated to be around 9,000-10,000 years old. The older bogs tend to be located in southern regions because those spots were released by the glacier ice earlier. But that's not a rule.
The water in the bogs is acidic due to the presence of sphagnum moss.
Bog water is really pure and potable, but it won't quench your thirst (remember, no minerals/nutrients!).
The acidic, oxygen-deprived environment in the ground preserves a wide range of objects, including tanks and even human bodies.
Some sources say that 22% of Estonia, or 1/5, is covered with bogs, fens, and wetlands. That's not true. This number includes all the peat/turf areas, including exploited mining sites. The actual number is somewhere around 6-7%. Most of those landscapes were destroyed by the Soviet Union.
In the past, local people have been afraid of bogs. Estonian folklore is full of stories about bogs or fen-related phenomena.

Photo author: Priidu Saart

Top 10 most popular bogs in Estonia

They say that you're never more than 15 minutes from a bog anywhere in Estonia, so this is just a small selection to choose from!

The story behind Estonians and their bogs

Estonians have seen the rise of the first bogs and the birth of the forests.

The oldest human settlement in Estonia is the Pulli settlement in Southwest Estonia. Scientists believe it to be somewhere between 10,000 and 11,000 years old. As said earlier, the oldest bogs are also 10,000 years old. So it appears that people here have been developing together with the landscape, which is not very common in other parts of the world.

This could be the reason why we have such a strong bond to nature. It's reflected in our culture as well. For example, we have a disproportionate amount of words describing natural sounds (wind and water). Although we have the longest relationship with bogs, it has been anything but stable. Interestingly, the perception of bogs among local people has been in constant flux. The way people see the bog today was unheard of 100 years ago.

Bogs as a source of food

In the beginning, before moss took over the shallow meltwater lakes, our forefathers used these waterways to navigate from one place to another.

Remember – the Ice Age had just ended, and a significant part of Estonia was below water level. Over the next few thousand years, the plants took over and started to form this spongy, ever-growing peat layer.

As the waterlogged areas turned into this weird hybrid landscape, people started to avoid them because it was easy to sink in, and getting through the bog was a real challenge. Besides the physical difficulty of getting through, this homogeneous landscape was tough to navigate. Everything looked similar, and there were no distinct points to rely on.

Photo author: Hans Markus Antson

One of the few people who visited bogs back then were hunters.

It might be surprising, but the heaviest animal in Estonia – the moose – prefers bogs and wetlands as its habitat. Open fields and challenging terrain provide it with space and shelter. Besides moose, different species of grouse live in the wetland as well. So those early hunter-gatherer tribes had to find their way through the bogs. According to the findings from the Pulli settlement, those early tribes hunted mostly beavers and moose. Hunting was the men's duty, so we can assume that a significant portion of those early communities didn't experience bogs at all. They just had to rely on others' stories.

Bog as refuge

Estonians lived as pagans until the 13th century, when a large campaign was organized by the Swedes, Danes, and Germans to conquer the eastern region of the Baltic Sea and bring Christianity there.

Historians claim that at the time, Estonian strongholds provided shelter to 6-9% of the entire population. As a result, 90+% of Estonians had to rely on natural refuges.

What place could be better to hide in than a bog?

Difficult terrain, easy to sink in (especially with horses and heavy artillery), easy to get lost... Suddenly, the terrifying bog turned into a shelter. The perception had changed.

You may wonder where people could hide in an open space. The answer is bog islands. Bog islands are hills that rise above the mossy surface of the bog. They are like oases in the desert. Usually, bog islands are covered with tall forest and provide a way more food than the bog.

Still curious about Estonian bogs? Head over to Romet's blog to read the rest of the story.