"Europe" as a cultural concept is substantially derived from the shared heritage of the Roman Empire and its culture. This shared cultural heritage is combined by overlapping indigenous national cultures and folklores, roughly divided into Slavic, Latin (Romance) and Germanic, but with several components not part of either of these group (notably Greek and Celtic). Cultural contact and mixtures characterise much of European regional cultures; Kaplan (2014) describes Europe as "embracing maximum cultural diversity at minimal geographical distances."