Trattoria Mario's is not for the faint-hearted. It is not the place for those who prefer a quiet dining experience with an elegant ambiance, a romantic view of the Ponte Vecchio, an impeccable wait staff, shiny silver cutlery and freshly pressed tablecloths and napkins. Mario's is chaotic, loud and cramped. You can't make reservations and you have no choice but to sit on wooden stools, elbow-to-elbow with strangers. It's open only at lunch and you'll be lucky enough to eat there before 1:30pm: the long queue is evident in the perennial mass of would-be customers standing around on via Rosina.