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,
Trans-European Airport network the poor quality of the inland transport infrastructure. Airports in all three categories are shown on this map (13 MB), p. 103 In addition to the above characteristics, International and Community connecting points should also be gradually linked to the Trans-European high-speed rail network, where appropriate. The network should include the infrastructures and the facilities which permit the integration of air and rail transport services and, where appropriate, maritime transport services. Trans-European Airport network The Trans-European Airport network is one of a number of the Trans-European Transport Networks (TEN-T) of the European Union. According to Article 13 of the Decision