The Eemian (also known as the Riss–Würm interglacial, among other local names) was one of the warmest interglacials of the last 800,000 years. One indication of what the climate was like at the time is the range of the common hippopotamus (Hippopotamus amphibius) – the same species that lives in Africa today – whose fossils have been found across much of Europe, as far north as Yorkshire in northern England.

Present-day Poland was then covered by forests dominated by deciduous trees such as oak, lime, hornbeam and elm, with shrubs including hazel. Holly and boxwood also grew here. The warm, humid climate supported numerous lakes. Mammal remains from this period are often found in lake sediments, which favoured the preservation of bone. Animals living in Poland during the Eemian included the huge straight-tusked elephant (Palaeoloxodon antiquus) and Merck’s rhinoceros (Stephanorhinus kirchbergensis), as well as species still found here today, such as red deer (Cervus elaphus), roe deer (Capreolus capreolus) and wild boar (Sus scrofa).