Ninfa is only opened eleven months in the year and only a few days each month. So if your visit to Rome doesn't coincide with one of its opening days, you won't get to visit it. I planned my trip for a whole year making sure my trip to Rome coincided with one of Ninfa's opening days. There were only a handful of us from outside Italy, the rest were Italians. It is the most beautiful and most romantic garden in the world.