If you like fountains, the gardens at the Villa d'Este, in Tivoli, Italy, are a must-see. The gardens are on the grounds of the former residence of Cardinal Ippolito d'Este. They were built in 1572. Today, this garden is part of the UNESCO world heritage list.
The garden is organized in terraces and steps. Visitors will see numerous fountains, grottos, and ponds. The Neptune fountain, pictured at the top, is the largest and most spectacular fountain. There's also an organ fountain, which, yes, plays organ music with the sounds of the falling water. If you'd like to hear it, the first playing is at 10:30 every day, and then it occurs every two hours.
The garden is open daily from 8:30 AM to 6:30 PM. Admission is 10 euros for adults.