By analyzing conceptual transfer this volume offers new insight in areal linguistics. Mainland Southeast Asia unifies great linguistic richness consisting of numerous languages and countless varieties of genetically diverse language families. Nevertheless, the area is known as a prime example for linguistic convergence. Exemplified by spatial reference in Thai, Khmer, Lao and Vietnamese, this study reveals conceptual borrowing due to language contact as an areal defining feature. The results from the field-based data analysis may help answer what extent cultural impact can be used as evidence for the existence of linguistic areas. A speaker’s cultural background might have a stronger impact on the choice of spatial language encoding than expected. Method and structure of argumentation can provide a model for similar questions addressing the existence of linguistic areas as well as to other cognitive dimensions within the Southeast Asian area under consideration. Therefore, the study can be seen as a significant contribution to analyze possibly existing conceptual areas empirically and exemplarily. Additionally, the investigation can serve as an important complement to empirical assumptions of conceptual transfer.