Bæjarins Beztu Pylsur
In a parking lot facing the harbor, this tiny yet famous fast-food hut is known for serving the original Icelandic hot dog—and a single person serves about a thousand of them a day from the window. Ask for eina með öllu (pronounced "ayn-ah med utl-lou"), or "one with everything," which gets you mustard, tomato sauce, rémoulade (mayonnaise with finely chopped pickles), and chopped raw and fried onions.