Nature, Published online: 29 January 2025; doi:10.1038/d41586-025-00190-4There is indirect evidence that, during the last interglacial period, about 125,000 years ago, parts of the West Antarctic Ice Sheet retreated. An ice core drilled from the ice sheet near the bordering Ronne Ice Shelf suggests that, contrary to some model reconstructions, the ice shelf survived this period at almost its current extent.