Cretaceous limestones near Maastricht (SE Netherlands) have been quarried at least since Roman times. In the late eighteenth century, scientific interest developed in their macrofossil content and specimens were illustrated for the first time. Amongst the early discoveries was a partial skull of a large predatory vertebrate that would play an important role in the emergence of modern palaeontology and our understanding of the concept of extinction. After decades of scientific debate, this animal was recognized as a large extinct marine relative of monitor lizards (varanoids) and named Mosasaurus. A detailed lithostratigraphy of Upper Cretaceous (Santonian–Maastrichtian) rocks was established in the Maastrichtian type area during the mid-1970s, which resulted in a renewed interest in fossil hunting by professional and amateur palaeontologists alike. During recent decades, both micro- and macrofossils have enabled a refinement of biozonations, correlations within the basin and with sections elsewhere, a greater insight into taphonomic processes and updated taxonomic interpretations. A new age model and chemostratigraphical framework is the most recent addition, permitting the placement of geoheritage in a larger frame and intensifying outreach to the public, including also virtual and augmented reality and hands-on experience to visitors of museum and (disused) quarries alike.