In the realm of giants

Many archaeological remains have been found in the Oulujoki river valley in the form of peculiar stone structures, mounds and castle-like ruins that have puzzled researchers. These ancient structures have been given various explanations and vernacular names, such as troll's castle, ancient castle, giant's church, giant's cave and giant's cauldron. Seven giant's churches are known in the Oulujoki river area. There are no similar relics anywhere else except in the coastal area of the Gulf of Bothnia.

A virtual model of the ancient giants of Pyhäkoski. Screenshot from the game "Pyhäkosken kuohuissa" ("Foams of Pyhäkoski Rapids"). Production: Clever Simulation Entertainment, Kajaani University of Applied Sciences Game Laboratory, 2023.

In old myths and stories, the Oulujoki river was the realm of giants. Local tales of giants have been recorded by authors including historian A. H. Snellman in 1887. Ancient inhabitants of the area tell stories of giants who were very large and powerful and had their heads near the tops of the trees.

Dwelling in caves and rock caverns, giants or mountain trolls have inhabited the wilderness before the arrival of humans. According to the stories, the giants did not oppose the arrival of humans on their lands but found churches an abomination. The giants fled north to escape their sphere of influence, but still protect their former homes in the form of invisible elves who sometimes do their chores during the night. They are said to have supernatural abilities that allow them to accomplish otherwise impossible undertakings.

Giant castle lords

Even before Snellman, surveyor Jakob Johan Wikar made notes of giant tracks and especially one giant’s castle located in Utajärvi in 1739. The mention is found on a map in the provincial archives of North Ostrobothnia, where the castle ruins are marked at a point between Sotkajärvi and Pälli on the southern bank of the river. The map has a note in old Swedish: An old castle, built by a giant in times gone by. You can see the foundation of large grey stones and earth, and even though it is overgrown you can see the wall and two gates.

A. H. Snellman has also written about the Sotkajärvi Castle later, recalling it was a “high land”, or a troll castle, built by the sons of giant Kaleva. Another author who recorded stories of giant called Kaleva that he had heard was reverend J. Calamnius in 1868.

Many folk tales still told in the river valley today talk about the giant Kaleva. According to the stories, Kaleva had twelve sons, three of whom built castles for themselves in the North: Soini on the site of the church in Liminka, Hiisi some distance east of Kajaani castle, and Äijä on the shore of the river in Pyhäkoski.

Other giants are known to have lived along the shores of the river near the Pyhäkoski rapids, where they used to sit on the banks. They needed no boat in the rapids, simply wading back and forth in the water when they built their dams. One used to sit on the Rakankallio rock, another on Leppikallio. There they talked to each other, and the roar of the rapids never drowned their voices from being heard. (Snellman 1887)

Giant's Island, Muhos. Panoramic view of the Giant's Church viewed from the east. Muhos. Photograph: H.‐P. Schulz 2012. Lusto – Finnish Forest Museum. Metsähallitus Forestry Cultural Heritage Inventory Collection. The Finnish Heritage Agency.

What were giant’s churches built for?

North of the river in the village of Sanginjoki there is a 200-by-400-metre forest island in the marsh: the giants’ island of Muhos. At its highest point is a Giant’s Church. A. H. Snellman quotes J. Calamnius in his report about the site, and it has also been studied as part of an archaeological inventory in 1985.

Ancient remains such as the giant’s church in Muhos, thought to be giant settlements, are often located on rocky slopes in the middle of marshes, far from the settlements. The sites were originally on or near the coast, but upheaval has lifted the structures far from the current seashore.

The structures are often oval or rectangular stone arrangements of various sizes. Some of them have walls between half a metre and two metres high, or sometimes two concentric walls. The walls usually have one or more doorways.

Archaeologists and researchers studying the history of the structures have estimated that they have been built approximately 2,500 years ago, or even earlier during the Neolithic period five thousand years ago. There are many estimates of their origin.

In the past it has been assumed that the structures served as defences and shelters against the enemy. This assumption is supported by the considerable amount of work involved in their construction, the location of the structures and the presence of double walls in some of them.

On the other hand, they have also been thought of as camp sites of fishermen and seal hunters, or even fish traps. It has also been suggested that the giant’s churches were a kind of calendar that was used to rotate hunting grounds according to seasons. Typically, the openings in their ramparts are aligned to the direction of sunrise and sunset, often considered an early way of understanding and structuring the universe.


Giant's Island, Muhos. View of the Giant's Church toward south-east. Photograph: Teemu Mökkönen 2020. Digital photo collection. Archaeological image collection. The Finnish Heritage Agency.

Oral tradition about disappearing structures

The ancient remains have also been thought to be sacrificial sites and graves used by the Lapps. There are other possible connections between Lapps and giants, such as Lapland graves, usually not actual graves but earthen pits from the Stone Age, which may have served as traps, cooking pits, dwellings or storage pits. In popular stories, the Lapps and the giants are often intertwined.

According to more recent research, some of the stone ruins could be boundary markers or navigation aids, while others are sacrificial graves or burial mounds. They have also been thought of as foundations of dwellings.

Many of the structures are still unstudied and unexplained, and some of the ruins have been lost or have crumbled away. Over time, people have used stones from the ancient structures as foundations of their dwellings, and in some places the stone structures have been destroyed. Over time, trees growing out of the ground have also moved the ruins.

In the absence of definitive research data, the importance of oral tradition is highlighted. The mythological heritage of the prehistoric stone ruins has been strengthened by stories about their prehistoric inhabitants passed down from one generation to the next. One of the most famous folk tales of the Oulu river valley is the story of Montta, the first individual to go down the Pyhäkoski rapids, and the end of the age of giants of the river.


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Giant's Island, Muhos. Latest change 30 March 2022. Archaeological sites. The Finnish Heritage Agency.

Karppinen, Väinö P. and Kesäniemi, Martti 1999. Muistojen kirja Muhokselta ("A Book of Memories from Muhos"). Muhos: Muhos Local Heritage Association.

Merilä, Aino 1993. Muinaisen linnan rauniot Utajärvellä ("The Ruins of an Ancient Castle in Utajärvi"). Oulun sukututkija ("Oulu Genealogist") 1993: 2. Origin: The Giant's Castle at Lake Sotkajärvi. Municipality of Utajärvi.

Oulujoki River Limited Company 1954. Entinen Oulujoki: historiikkia ja muistitietoa ("The Oulujoki River of Old: Histories and Recollections").

Snellman, A. H. 1887. Oulun kihlakunta: muinaistieteellisiä ja historiallisia lehtiä ("Oulu Parish: Ancient and Historical Journals"). Suomen Muinaismuistoyhdistyksen Aikakauskirja IX ("Journal of the Finnish Society of Antiquities IX"). Helsinki: SKS.

Taskinen, Helena. Muhos inventories 1985 and 1986. The Finnish Heritage Agency.

Vilkuna, Kustaa 1965. Kiviraunion historia ("History of a Stone Ruin"). Kotiseutu, issue 5 (page 88). Forssa.