Slate mining defined the history of Elm and the Sernft Valley right up into the 19th century. Today the "Landesplattenberg Engi", a former slate mine, is open for guided tours.

The entrance to the mine which takes the visitor right into the mountain lies two hundred metres above the valley. After a few metres, visitors encounter huge, 20-metre-high halls supported by slate pillars that serve to prop up the hollowed-out mountain. The impression of such spaces takes your breath away. In Elm, a small slate factory has been preserved; this has been turned into a museum. Each stage of production, from the drawing of lines to the framing of the small slate tablets is replicated and explained during tours through the old hand-finishing areas.

In the Sernftal in Glarus nowadays, they make slate furniture, watches and accessories (e.g. genuine school slates) out of slate extracted from the Landesplattenberg Engi slate mine, mostly unique products hand-made by various local craftsmen. These products can be purchased directly from the producers or at the exhibition in the Landesplattenberg pavilion in Engi-Hinterdorf.