Traces of Finland's Ice Age

A landscape shaped by ice

Finland's landscape still bears the fingerprint of the continental glacier. The last Ice Age in Finland ended about 10,000 years ago, and at its peak the ice was kilometres thick. The melting ice and waters flowing beneath it shaped the ground in many ways: sand and gravel formed long eskers, meltwater whirlpools carved circular giant's kettles in the rock, and the glacier transported blocks that became erratic boulders and strange boulders, left behind far from their original location. In some places, blocks of ice buried at the glacier's edge left deep kettle holes in the ground as they melted. Land uplift continues in Finland, and it continuously reveals new shoreline from the former seafloor during the Ice Age.

Discoveries and research

The narrow Punkaharju esker attracted travellers as early as the 19th century, and Russian Emperor Nicholas I was so impressed by the area that he ordered it protected in 1843 – one of Finland's earliest nature conservation decisions. Giant's kettles have also been studied scientifically: in 1996 the Geological Survey of Finland drained Salla's largest kettle, Juomapata, from the Aholanvaara area to conduct research. The kettles at Pihlajamäki in Helsinki, in turn, are reportedly Finland's oldest, formed even before the last glaciation.

Most interesting sites

The traces vary from long eskers to stone-paved paths and deep holes.

• Punkaharju, Savonlinna – a seven-kilometre esker, one of Finland's national landscapes.
• Aholanvaaran giant's kettles, Salla – the group contains what is known as Finland's largest kettle, Juomapata.
• Askolan giant's kettles, Askola – twenty kettles on the same rock face, the largest over four metres wide.
• Kummakivi, Ruokolahti – an approximately 500-tonne erratic boulder resting on rock with only a narrow contact surface.
• Syvyydenkaivo, Utajärvi – Finland's largest naturally occurring kettle hole, over 50 metres deep.
• Jättiläisen tie, Vaasa – a 49-metre stone-paved path in Vähäkyrö built as early as the late 500s.
• Jääkausipolku, Parikkala – a 17-kilometre route with a large kettle hole named Huttumalja.

Where the traces are most visible

Sites are found throughout the country, but they cluster clearly on a few ridges. Lapland, and especially Salla, stands out: the area has several groups of giant's kettles, gorges, and ridge trails in the same region. In southern Finland, the Salpausselkä marginal formations run around the Lahti region, where numerous marked trails cross them. In the capital region, particularly in Helsinki, there are also several giant's kettle occurrences in the urban landscape. Eskers and their observation towers repeat in Kangasalla, Hämeenlinna, and central Finland, where the glacier's direction of movement left long, narrow ridges in the landscape.

Before you go

Most sites are freely accessible year-round, but many routes traverse sensitive terrain. Some duckboards and rock faces can be slippery, especially in autumn and after rain, and caution should be taken on steep esker slopes and around kettle hole edges. Giant's kettles and erratic boulders are often protected by nature conservation law, so they must not be damaged or climbed. Stay on marked nature trails to preserve the sensitive vegetation and rock surface. Some sites are located far from populated areas, so good shoes, a map, and sufficient time should be reserved in advance.