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,
Burgas Airport Burgas Airport Burgas Airport () is an international airport in southeast Bulgaria and the second largest airport in the country. The airport is located near to the north neighbourhood of Burgas, Sarafovo, which is located approximately 10 kilometres from the city centre. The airport serves Burgas and seaside resorts of Bulgarian south coast and is a major destination during the European summer leisure season. In 2017, the airport handled 2,982,339 passengers, a 3.6% increase compared to 2016. On 27 June 1937 the French company CIDNA (now part of Air France), chose the area of Burgas Airport to build a radio