New York City's Diamond District occupies West 47 Street between Fifth and Sixth Avenues. This one block has 2600 diamond and jewelry merchants whose daily revenue is estimated at 400 million dollars.
http://www.diamonddistrict.org
In "Marathon Man", Laurence Olivier's character visits Manhattan's Diamond District where someone recognizes him as "The White Angel" of Auschwitz; a Nazi war criminal:
http://www.youtube.com/watch?v=2ybpsRNXUII