How it is that visitors to New Orleans somehow hear about this cafe is a mystery. It looks like any of dozens of other sandwich-and-platter shops in the French Quarter. But they do, and although the lines aren't as consistent as they once were, it's still always busy. The sandwiches are somewhere between poor boys and deli. The prices would be a bargain even outside the French Quarter. Important: this is not to be confused with the nearby Pierre Maspero's, a different, unrelated restaurant.
In 1971, Charlie Malachias took over a historic restaurant space in a late-1700s building on the corner of Chartres and St. Louis. The cafe was operated from by Pierre Maspero, and was a meeting place of some of the most famous and colorful figures in early New Orleans history. Malachias began serving much the same menu there now--which, in those days, was offbeat in New Orleans. Cafe Maspero moved to its present location--the square root of two blocks from the old one--in the 1980s. (It has no connection with the Pierre Maspero's that took over the old place.)
On large room with an open kitchen and tile floors, with an open kitchen in the back and big tables jammed in maximum numbers. Although large French doors open to the street corner on both sides, the restaurant is a little dark even in daytime. The service staff is always on the run, but gets the orders in and out efficiently.
If the line is long, go elsewhere. It's good, but not that good. Unless the undeniably fine value is of importance to you.