Siebenbrünnen, Karst spring formation in Lenk, Switzerland

Siebenbrünnen is a karst spring on the Rezliberg alp at 1,405 metres, at the foot of the Wildstrubel in the municipality of Lenk. Water leaves a rock cleft in seven main jets and forms the source of the Simme. The spring is fed by meltwater from the Rezliglacier, so its flow varies little over the year.

The springs are a karst spring at the foot of the Wildstrubel on the Rezliberg, on the municipal territory of Lenk. Their water comes from the Plaine Morte glacier about 3 km to the south and some 1,300 m higher, emerging through a rock cleft in seven main jets. Because this glacier feeds them continuously, their flow varies little over the year, which is unusual for karst springs.

The name Siebenbrünnen, also written Siebenbrunnen, Siebe Brunne or Bi de Siebe Brünne, refers to the seven main jets leaving the rock cleft; French speakers call the site Sept fontaines de la Simme. The spring rises on the alp Rezliberg, also spelled Räzliberg, above Lenk, and its water forms the Simme.

The springs are reachable via marked hiking trails from Lenk, with the best access during summer months from June to September. The well-maintained paths make navigation straightforward throughout this period.

The spring water originates from the Plaine Morte glacier and travels underground for about 3 kilometers before emerging through the seven openings. This underground journey demonstrates how karst systems function in alpine environments.