Which painting by Edward Hopper illustrates urban loneliness?

Nighthawks

"Nighthawks" is much more than a mere depiction of urban loneliness. Hopper was inspired by a diner on Greenwich Avenue in New York's Greenwich Village neighborhood, but he chose to remove all the doors! The absence of doors on the diner's facade, as seen in the painting, perhaps symbolizes an invisible barrier between the people inside and the outside world, accentuating the sense of isolation. This subtle yet powerful touch invites deeper reflection on isolation and human connection in metropolises.