From the Wikipedia page 
Charing Cross denotes the junction of Strand, Whitehall and Cockspur Street, just south of Trafalgar Square in central London, England. It is named after the now demolished Eleanor cross that stood there, in what was once the hamlet of Charing. The site of the cross is now occupied by an equestrian statue of King Charles I. Since the second half of the 18th century Charing Cross has been seen as the centre of London. It is the primary of the central datum points for measuring distances from London along with the London Stone, Hicks Hall and the doors of St Mary-le-Bow church.