Also known as the Smugglers' Moon. It is the alleged birth place of bounty hunter Aurra Sing, and plays a rather large role in the game Knights of the Old Republic 2.
Within the largest city, there lies such locations as the Cantina, and the Jek-Jek Tar. The Jek-Jek Tar is a bar strictly for aliens, in which they come to inhale chemicals which are reminiscent of the environments of their homeland. As these chemicals are harmful to human beings, they are cautioned to stay out.
Another notable location is the shipyard, in which numerous bounty hunter's and smugglers meet to fill contracts and do business. Although there are more upper-class cities located on the moon, most of Nar Shaddaa is considered a slum environment, where criminals and bounty hunters alike are born and fueled.