RESEARCH HIGHLIGHT23 September 2026One-tonne cache of iron is the largest ever found — and enough to make roughly 500 swords.Save articleView saved researchThese iron bars were initially found by workers excavating gravel in northern Austria. Credit: Peter Trebsche, Universität InnsbruckIron was central to life in Europe in the second and third century bc, but the scale of its production and trade has been unclear. The discovery of a “rusty treasure” from Austria now suggests that more than a tonne of the metal was being shipped along the River Danube during the Iron Age, around 2,200 years ago1.Access options Access through your institutionAccess Nature and 54 other Nature Portfolio journalsGet Nature+, our best-value online-access subscription27,99 € / 30 dayscancel any timeLearn moreSubscribe to this journalReceive 52 print issues and online access199,00 € per yearonly 3,83 € per issueLearn moreRent or buy this articlePrices vary by article typefrom$1.95to$39.95Learn morePrices may be subject to local taxes which are calculated during checkoutdoi: https://doi.org/10.1038/d41586-026-02986-4ReferencesTrebsche, P. & Berranger, M. Antiquity https://doi.org/10.15184/aqy.2026.10404 (2026).Article Google Scholar Download referencesSubjectsArchaeologyLatest on:ArchaeologyJobs Associate or Senior Editor, Nature Mechanical EngineeringJob Title: Associate or Senior Editor, Nature Mechanical Engineering Location: Beijing, Shanghai and Milan - Hybrid Working Model. Closing date:...Beijing, Shanghai and Milan - Hybrid Working Model.Springer Nature LtdAssociate or Senior Editor, Nature CommunicationsJob title: Associate or Senior Editor, Nature Communications (Human Behaviour team) Locations: Shanghai, Berlin or Pune (hybrid) Closing date: 11th...Shanghai, Berlin or Pune (hybrid)Springer Nature Ltd