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,
Swansboro Country Airport Swansboro Country Airport Swansboro Country Airport is four air miles (6 km) northeast of Placerville, in El Dorado County, California. It is owned by the Swansboro Country Property Owners Association. Most U.S. airports use the same three-letter location identifier for the FAA and IATA, but Swansboro is 01CL to the FAA and has no IATA code. Swansboro Country Airport covers and has one asphalt runway, 9/27, which is . The runways slopes downhill to the west. Night operations are prohibited, and is unattended. The airport has 25 aircraft are based at the airport: 21 single engine, 3 multi-engine and 1