Soho is the name of districts of London and of New York City.
Soho is a district of the West End in central London, and for administrative purposes is part of the City of Westminster. It is supposedly named after a hunting cry - "So! Ho!" - dating from the time when the area was a rural district outside the city. It was developed with streets and squares in the seventeenth and eighteenth centuries, and its boundaries are now commonly accepted to be Oxford Street, Tottenham Court Road, Shaftesbury Avenue, Piccadilly Circus, and Regent Street. In the nineteenth century it was a district populated by immigrants and refugees - Karl Marx lived there for a time - and it became known for a cosmopolitan atmosphere and a large number of restaurants from around the world. In the mid twentieth century it gained an unsavoury reputation for prostitution and pornographic cinemas and bookshops, but has since been, to an extent, 'cleaned up'.
Soho is a neighborhood in downtown Manhattan. Its bounds are, roughly, Houston Street to the north (the name Soho is a contraction of "south of Houston"), Lafayette Street to the east, Canal Street to the south, and Sixth Avenue to the west. Soho is noted for its historic cast-iron buildings, art galleries, and exclusive shops.