The stretch of Fifth Avenue outside the Metropolitan Museum of Art  thronged by tourists but without a restaurant in sight  could be the most coveted location for selling a hot dog in New York.

The city once earned more than half a million dollars a year in vending rights from two hot dog carts in front of the museum. Then, two years ago, a third vendor, Dan Rossi, nosed his cart onto the property, saying that as a disabled veteran, he had the right to be there without paying the city a dime.

Mr. Rossi has held his ground, but he has also inadvertently prepared the way for other veterans. So this summer, visitors spilling out onto the plaza beneath the museum’s soaring Corinthian columns have stumbled into not two or three carts, but a small flotilla.

On Friday, eight were drawn up around the broad stone steps, and not one of them was paying to be there.