The nature reserve, which is significant throughout Europe due to its special flora and fauna, can be found in the wide open hollow of the Ehegrund south of Markt Nordheim. It encompasses two different protected objects on 10 ha, the origin of which can be traced back to the karstification of powerful plaster sticks in the clayey myophoria layers of the Gipskeupers. The "Höllern" plaster cave consists of two extensive cave systems. It is the only known leachable cave of the Gipskeuper in southern Germany.
The cave system is winter quarters for bats. The cave is unfortunately not open to the public. The gypsum hills of the “Seven Humps” line the edges of a railing channel that has broken into the subsurface. Relics of post-glacial Steppenheide flora grow here with the characteristic feather grasses. In April and May, the golden yellow flowers of the spring adonis bloom. Further beautiful flowering phases extend well into September, when the lime asters with their blue-purple tongue and yellow tubular flowers woo attention. The intermediate and border areas are extensively mowed or grazed, here
will continue to develop lean grasslands in the future.