Central City/Black Hawk Historic District Central City/Black Hawk Historic District The Central City/Black Hawk Historic District is a National Historic Landmark District that encompasses Central City and Black Hawk, Colorado. They are adjacent former gold mining camps in the Front Range of the Rocky Mountains in Gilpin County, Colorado, United States. For a time, the area was known as the Richest Square Mile on Earth. The district was designated a National Historic Landmark on July 4, 1961. On May 5, 1859, John H. Gregory discovered a rich deposit of gold in hard rock, the first such discovery in the Rocky Mountain region. Thousands of miners
Central London Railway 1939 were converted for use as a protected control centre for the Central Electricity Board. Central London Railway The Central London Railway (CLR), also known as the Twopenny Tube, was a deep-level, underground "tube" railway that opened in London in 1900. The CLR's tunnels and stations form the central section of the London Underground's Central line. The railway company was established in 1889, funding for construction was obtained in 1895 through a syndicate of financiers and work took place from 1896 to 1900. When opened, the CLR served 13 stations and ran completely underground in a pair of tunnels for