A nuclear waste storage facility needs to be secure, even if glaciers were to churn down from the Alps into the midlands in a distant future. This is why Nagra arranged for a study of the sediments that had been deposited in former, deep glacial lakes. The layers are around 600,000 years old, making them much older than the last ice age, which was around 24,000 years ago. Good news for Nagra: it seems that the layers of stone lying beneath have not been eroded by ice since that time.