We present five new sediment cores, the Rates of Interglacial Sea-level Change and Responses (RISeR) cores, extracted from the southern North Sea. The cores will allow us to study the evolution of the basin in the Quaternary (the last 2.58 million years). The cores reveal widespread soil, wetland, and river deposits, reflecting a lost, predominantly terrestrial, landscape that now sits around 20 m below sea level. Understanding these landscapes is vital, as they form the foundations for a rapidly growing offshore wind industry.