Siljan Ring 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 the Devonian period, about 376.8 ± 1.7 Ma. This coincides around the first Devonian extinction, the Kellwasser Event or Late Frasnian extinction at 376.1 Ma ± 1.6 Ma. The effects of the impact can clearly be seen in the bedrock in the area. The Cambrian,
Siege of Mora western border with Nigeria, was guarded by a company of "Schutztruppen" (protection troops) under the command of Captain Ernst von Raben. Initially the garrison consisted of 14 European and 125 African soldiers, most of whom were tough, well-trained Askaris. Von Raben managed to recruit 65 more men before the Allied siege began. On 13 August, the German commander relocated the garrison from the fort on the plain to positions partway up Mora mountain. This gave them a commanding view over the surrounding area and easy access to water. Mora mountain, which would become a fortress during the siege, was approximately