Did you know that the shells you pick up on the beach in the Netherlands are about 5,000 years old? "It is because shells are continuously reworked by waves and transported from one place to the other", says Frank Wesselingh from Naturalis Biodiversity Center in this podcast. It forms the perfect introduction to an interesting discovery done in a borehole drilled in Friesland; a discovery Frank tells a bit more about in this podcast. The moluscs the researchers found in the so-called Luxwoude borehole are also reworked, but they are much older than 5,000 years. Based on various stratigraphic criteria, the team concluded that the age of these moluscs is likely to be around 400,000 years, so Middle Pleistocene. And interestingly, these fossils indicate a warm climate, warmer than today's conditions. Learn more and listen to this podcast!