The Lower Paleolithic sites in the open-cast lignite mine of Schöningen, eastern Lower Saxony, have become internationally renown because of their worldwide oldest wooden hunting weapons associated with abundant faunal remains. These findings indicate hitherto unknown organized hunting and complex and abstract thinking of Homo heidelbergensis. Embedding in sediments of a former lakeshore led to an exceptional preservation of remains of an outstanding diverse flora and fauna. Concurrently, the extraordinary complete sequence of Middle Pleistocene sediments allows a high-resolution climate and environmental reconstruction of a mid interglacial to early glacial about 300,000 years ago. We propose to investigate aquatic microfossils (diatoms, ostracodes, gyrogonites of charophytes) as well as pollen and non-pollen palynomorphs along with sedimentological and geochemical parameters of five stacked lacustrine sequences of the Reinsdorf Interglacial and subsequent early glacial in order to address the following three interlinked topics: (1) A high-resolution reconstruction of climatic and environmental variability during the interglacial and into the early glacial period and the correlation with other northern hemisphere terrestrial and marine sites will result in a better understanding of the natural climate evolution of a terminating interglacial and contribute to clarify the controversial stratigraphic classification of the archeological sites and deposits. (2) Lake level reconstructions and characterization of the depositional environment are proposed to detect the lakes development and to assess underlying causes. (3) Using samples from the archeological layer 13 II-4, preserved in sediment blocks, a detailed 2D reconstruction of the habitat structure of the litoral zone of the paleo-lake will be performed in order to assess the environment and hunting strategies of Homo heidelbergensis and evaluate the embedding conditions of artifacts. By combining geobiological, geochemical and archeological results we propose to contribute to a more consistent picture of Pleistocene climate development and the habitat of early humans and their cognitive skills, and to clarify the stratigraphical position of these Middle Pleistocene deposits.