Siljan Ring proved inconclusive. Drilling for natural gas was resumed in the late 2000s and continues as of mid-2012. The scientific premise for prospecting of this sort is based on the work of physicist Vladimir Kutcherov, who is cooperating with Igrene, the company financing the drilling operations. Siljan Ring The Siljan Ring () is a prehistoric impact crater in Dalarna, central Sweden. It is one of the 15 largest known impact craters on Earth and the largest in Europe, with a diameter of about . The impact that created the Siljan Ring occurred when a meteorite collided with the Earth's surface during
Siljan, Norway Siljan, Norway Siljan is a municipality in Telemark county, Norway. It is part of the traditional region of Grenland. The administrative centre of the municipality is the village of Siljan. The parish of "Slemdal" was established as a municipality on 1 January 1838 (see formannskapsdistrikt). The name was later changed to Siljan. The municipality is located northeast of Skien and borders Buskerud county in the north and Vestfold county in the east. There is a forest district on both sides of Skiensvassdraget (Skien river). The older main road to Skien, Larvik, and Oslo, passes through Siljan. The municipality (originally the