Central City/Black Hawk Historic District and funds as a result. 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
City of London up the centre of the Thames, with the exception that Blackfriars Bridge falls within the City; the City controls London Bridge (as part of Bridge ward) but only half of the river underneath it, a feature which is unique in British local administration. The boundaries are marked by black bollards bearing the City's emblem, and by dragon boundary marks at major entrances, such as Holborn. A more substantial monument marks the boundary at Temple Bar on Fleet Street. In some places the financial district extends slightly beyond the boundaries, notably to the north and east, into the London Boroughs of