Predystoria is a historical and genealogical portal devoted to family history and the cultural heritage of Eastern Siberia, Transbaikalia, the Russian Far East, and neighboring regions, including Irkutsk Oblast. Combining an information resource, reference library, and active research community, it helps users investigate their ancestry, explore local history, and preserve historical records. Its forum, established in 2005, brings together thousands of discussions, archival materials, and research findings.

The portal offers family-history forums, guidance on tracing relatives, and resources for organizing family archives and stories. Its historical and local-history sections cover Transbaikalia, the Cossacks, Indigenous peoples, Old Believers, settlements, churches, and regional connections with Buryatia, Mongolia, and China. Visitors can access archival descriptions and document texts, historical and contemporary photographs, and a library of books about the region. Predystoria also provides educational material on reading old Russian cursive and interpreting archival documents. Members can share discoveries, ask questions, and receive support from other researchers. Registration gives users access to the full collection of materials and tools.