De Voltaire à Rousseau is a small bar near Louvre Rivoli station in Paris that serves wine, beer, cocktails and simple platters. Its signature cocktail is the gin sour, and cheese and meat platters and croque monsieur are also served. The bar stays open until 5 a.m., and guests can choose the music that plays, which suits late visits. The interior is very small, so it gets cramped when groups arrive at once.