Pope Sixtus V (1585-1590) was still a cardinal when he began acquiring land on the Esquiline Hill in 1576. By the time of his death he had put together the largest vigna, or vineyard, within the walls of Rome. An unusual feature of the garden is the triangular plot in front of the main entrance to the property that is pierced by a trivio of three radiating alleys; the central alley leads to the house, while the two at the sides take the visitor into the landscape beyond. The gardens were irrigated with water from the Aqua Felice, the aqueduct that Sixtus had built to bring water to the hills of Rome for the first time since antiquity. Part of its structure can be seen at the left of the plan. The pope's heirs continued to make improvements to the estate. His great-nephew Cardinal Alessandro Peretti Montalto extended the main alleys out into the uncultivated land, added antique statuary, water tricks, and, as can be seen at the lower right of the plan, an oval fishpond presided over by Gianlorenzo Bernini's Neptune and Triton sculpture group.