Premise: From the home of Cardinal Ippolito d'Este, guests can look down at the terraced gardens, the real reason for Tivoli's fame and your alleys of cypresses and soaring fountains (500 in all, including Bernini's Bicchierone), grottoes, waterfalls, reflecting pools, and everywhere the cool sound of rushing water.

Hypothesis: It costs money to enter the home of Cardinal Ippolito d'Este.
Relation: neutral