Schlangenberg, Nature reserve in Stolberg, Germany

Schlangenberg is a 123-hectare nature reserve east of Stolberg, centred on a 276-metre hill of Devonian limestone. The rounded, grass-covered hill rises above a gravel path, with a small dark structure near its flat top. The soil holds zinc and lead from centuries of mining, and the calamine flora includes Viola calaminaria and Thlaspi calaminare.

Celts and Romans mined calamine here; 25 coins dated 100 BC to 92/93 AD and Roman wall remains were found. Before 1800 ore was dug from surface pits; from 1800 shafts reached 105 m, drained via the Vichtbach. Around 700 miners, 200 of them hewers, extracted up to 6,600 tonnes a year. Mining stopped in 1871, restarted in 1881 and ended for good in 1883; the last headframe stood until 1915 and was demolished in 1921.

The reserve's German name means "snake mountain", after the smooth snake (Coronella austriaca) that still turns up here. Local volunteers and the Biologische Station im Kreis Aachen cut back pines that would otherwise overgrow the calamine turf, and a local group ran a museum on the mining past with animal and flower exhibits.

There are no marked trails or information centre; visitors themselves have worn informal paths that damage the calamine flora, so stay on existing tracks and avoid stepping on the open ground. The reserve lies near Breinigerberg, east of Stolberg, with the 276 m hill reached along the L12. Volunteers and the Biologische Station im Kreis Aachen cut back pines that would otherwise overgrow the site.

The reserve's German nickname is Balkan, earned by the bare, contaminated ground left after mining. The hill also gave its name to the rare snake Coronella austriaca, the snake-mountain namesake occasionally found here. More than 300 butterfly species have been recorded, some feeding only on calamine-tolerant plants.