A geopark focusses on the geological heritage. Due to its particular geology, the Natur- & Geopark Mëllerdall is also a geopark. The rocks have created the Mullerthal Region known beyond its borders. The landscape is very attractive which is due to the small-scale alternation of plateaus, gently undulating hilly landscapes and deeply incised valleys. The distribution of fields, meadows and forests was influenced by these landscape forms. The shape and use of today's landscape are the result of a long development. The geological history started 250 million years ago. The current landscape has emerged over the past 20 million years and the use by humans has been documented since the Stone Age.

The Luxembourg sandstone landscape from the Lias period in the center of the region is one of the most impressive in Western Europe. To the east and west, marl and dolomite from the shell limestone period form the subsoil.

The goals of the Natur- & Geopark Mëllerdall are diverse. The main objective is to sustainably develop the region as a whole. That means getting involved on an ecological, economic and social level by implementing appropriate projects or offering specialist advice. This know how of its employees enables the Natur- & Geopark Mëllerdall to support regional companies and thus the regional economy in various areas (e.g. production, marketing, presentation), including geotourism. The inhabitants of the region in particular are being sensitized about their environment. Various activities for children and adults are offered in the course of the year: for example trainings and hikes, but also larger events such as the Natur- & Geopark Mëllerdall Week.

In an UNESCO Global Geopark too, geology and other regional peculiarities help to sensitize the population and the visitors to the environment and to strengthen the regional identity. This is done in a holistic approach to protection, education and sustainable regional development. Only a region with a geological heritage of internationally recognized geoscientific importance can apply for the UNESCO Global Geoparks program. In this process, the region has to face a critical selection process. If the outcome is positive, they are awarded the UNESCO Global Geoparks label for 4 years and after that have to renew it every 4 years.