Nature reserves constitute one of the most important conservation categories in Germany and Austria. The exact definitions vary, but together they combine the conservation of natural landscape, the protection of endangered species and the preservation for scientific interests.
The two relatively small nature reserves Martinswand (approx. 54 ha) and Fragenstein (approx. 8 ha) in the Zirl - Innsbruck area occupy a special position in climatic and geographic terms. The local climatic ("hot") special position leads to an inner-alpine, continental dry vegetation with heat-loving shrubs and dry grasslands. This "Föhnflora" is characterized by some southern warmth-vectors, which are hardly found elsewhere in North Tyrol, and can rightly be called the "Botanical El Dorado" for Tyrol.