lake Inkwil, Paleolithic open-air station / Neolithic and Bronze Age lakeside settlement

Lake Inkwil (Inkwilersee) in Inkwil is a small, shallow lake on the border between the Swiss cantons of Bern and Solothurn. It is one of the places where people built lakeside settlements for thousands of years. The island in the lake belongs to the prehistoric pile-dwelling sites on the UNESCO World Heritage list, and it is also a nature reserve. It suits visitors who like archaeology and quiet water landscapes in the Oberaargau region.

Where is Lake Inkwil?

The lake lies between the villages of Inkwil (canton of Bern) and Bolken (canton of Solothurn), at roughly 47.199 N, 7.663 E. Its large island is split about equally between the two municipalities, so the archaeological services of both cantons look after it together. The lake is a moraine lake left by the last Ice Age. It is slowly silting up and is barely more than 5 metres deep at its deepest point.

What lies beneath the island?

Cultural layers and wooden piles from former buildings survive in the island and the lake bed. Archaeologists trace the earliest settlement to the Neolithic, from about 3800 BC. Activity peaked in the Late Bronze Age, around 1000 to 850 BC. Iron Age and Roman-period finds have also turned up. One of the most striking discoveries is a rare Bronze Age wooden sword, recovered during a dive by Bern's underwater archaeologists.

Waterlogged mud shuts out oxygen and preserves wood and organic material, which is why such sites reveal far more than dry-land settlements. The site has been part of the UNESCO "Prehistoric Pile Dwellings around the Alps" listing since 2011.

Why did the lake make the news?

In 2018 divers from Bern's cantonal archaeological service found that beavers had dug tunnels into the island, cutting through prehistoric layers and timbers. Both cantons approved a protective grid around the island, with costs put at about 800,000 Swiss francs. An exhibition notice says the island has been protected from beavers since December 2025.

How should you visit?

The protected zone covers the whole island and the lake bed next to it, so this is a place to view from the shore, not to explore. Do not expect a reconstructed village or an on-site museum. Information boards and material from the Bern and Solothurn archaeological services give the background. Keep quiet and stay out of the reserve, which is habitat for waterbirds and beavers.

Frequently asked questions

Is Lake Inkwil in Bern or Solothurn?

Both. The lake sits on the cantonal border, and the island is shared by Inkwil (Bern) and Bolken (Solothurn).

How old is the settlement?

Traces go back to the Neolithic, about 3800 BC. The densest occupation came in the Late Bronze Age, around 1000 to 850 BC.

Can you walk onto the island?

No. The island is a protected nature reserve and archaeological site, so visitors look at it from the shore.

Is the site a UNESCO World Heritage Site?

Yes. It is part of the "Prehistoric Pile Dwellings around the Alps" listing, inscribed in 2011.