Los Vegas refers to Las Vegas and expresses how in Las Vegas typical rules are not necessarily followed or
obeyed. The word "vegas" in Spanish is feminine so the "las" is meant to
precede it by the rules of Spanish grammar.
So, to express how conventional rules are broken in Las Vegas, Los Vegas can be used to also refer to the city.
Instead of the saying, "
What happens in Vegas,
stays in Vegas," one could express the same saying, "What happens in
Los Vegas stays in Los Vegas."