The boulevard bears on &mdash past the glass-domed Grand Palais, through the Place de la Concorde &mdash  and pulls up at the foot of a long manicured park, the Jardins des Tuileries. Beyond is the Louvre. The halls of the Louvre itself are vast, but they seem to overflow onto the Tuileries, which are studded with sculpture, as though art were music, and the Louvre a powerful boombox. Between the fountains, the Rodins and the sunbathers, the Tuileries in the summer fit a pretty uncontroversial idea of paradise. Given the horizon-to-horizon expanse of things to do in summertime Paris, there is only one categorical imperative eat sorbet. Your basic lemon sorbet, eaten in the sun, is so electrifyingly good it leaves the mouth tingling like a bell for seconds after each lick. If you&rsquore thirsty afterward, or homesick, find the pack of lads from Haryana, here illegally via Moscow, who control the bottled-water trade in the front courtyard of the Louvre.