The Rheinisches Mühlen-Dokumentationszentrum e.V. (RMDZ) is a registered non-profit organization dedicated to preserving the rich history and technology of mills, particularly in North Rhine-Westphalia, Germany. Operated by a dedicated team of volunteers, RMDZ focuses on documenting, researching, and promoting the cultural significance of mills as an essential part of regional heritage.

Through meticulous research, the organization catalogs visible architectural and mechanical artifacts of mills, creating an extensive inventory that reflects the evolving mill technology over time. RMDZ's commitment to accessibility ensures that these findings are shared with the public through various publications, including technical and historical documentation, annual reports, and research papers.

The center engages in diverse projects that explore the socio-cultural aspects of mills and their role in local history. RMDZ not only fosters appreciation for this unique cultural heritage but also engages the community by making its findings available to a wider audience.