The villa also housed some of the great art treasures of Florence, including Sandro Botticelli's Renaissance masterpieces The Birth of Venus and Primavera.
A fortified building had been standing on the site since at least 1427, and was purchased in 1477 by Lorenzo and his brother Giovanni di Pierfrancesco de' Medici.
This the year after their father died at the age of 46, leaving the young boys wards of their cousin Lorenzo il Magnifico, of the senior branch of the Medici family and de facto ruler of Florence.
As the architect and writer Giorgio Vasari wrote, "At this place the Duke began to build a little, one thing after another, to the end that he might reside there more commodiously, himself and his court.
First, under the direction of Piero da San Casciano, an aqueduct was constructed from the Castella higher up the slope of Monte Morello to a small reservoir he built on the hill above the villa.
In the center of the reservoir above the garden, in the "sacred wood," was a statue of Appenino, symbolizing the mountains of Tuscany, portrayed as an old man shivering, with water pouring over his head.
Water flowed from the reservoir down bronze pipes and emerged in two fountains built in the retaining wall on either side of grotto, representing the two rivers of Florence.
The garden was designed to deliver a clear political message; that, after a long period of warfare and suffering, Cosimo was going to lead Florence into a new Golden Age, with peace, prosperity, and harmony.
Tribolo planned to place other statues around the gardens representing the four seasons, and the virtues of the House of Medici: justice, compassion, valor, nobility, wisdom, and liberality.
Cosimo's letters report that he spent many long summer afternoons with his family, enjoying the coolness of the shade and the fountains.
Don Lorenzo de' Medici commissioned the painter Il Volterrano to decorate the villa with a fresco, Vigilance and Sleep, in 1640.
Cosimo III de' Medici, deeply interested in botany, introduced a very rare species of Indian jasmine, called mugherino, in 1688, and built a special greenhouse to protect it in winter.
[6] During the Medici years, many foreign travelers, including Michel de Montaigne and the botanist Pierre Belon, visited the villa and wrote descriptions, which made it known throughout Europe.
The statue symbolized the victory of Cosimo de' Medici over the enemies of Florence, particularly the rebels who tried to depose him in the early months after he became Duke.
Around the base were marble statues of children, life sized and in full relief, protected by the tazza, or basin above as if they were sheltering from the rain.
The fountain of Florence, or Fiorenza, was originally located in the upper part of the garden, closer to the grotto, and it was surrounded by a maze of greenery.
The walls of the cave were covered with limestone molded to resemble a natural cavern, embedded with stones, mosaic and seashells.
The cultivation of citrus trees in Europe had begun in the mid-15th century, and was carried out on a large scale at Villa di Castello.
Next to the ortaccio is a small classical-style hothouse, built in the late 18th century to house exotic flowers, particularly the rare double jasmine from Goa, in India, which Cosimo III de'Medici introduced to Florence in 1688.
During the life of Cosimo, the house was famous for its works of art, particularly the Botticelli Birth of Venus and Primavera, which were located there before 1550, and later moved to the Uffizi.
It also included a cycle of paintings by Pontormo made in the loggia between 1538 and 1543, depicting the Return of the Golden Age, no longer existing.
It now is the headquarters of the Accademia della Crusta and the Opera del Vocabalario Italiano, two associations devoted to the Italian language and literature.
In Italy, Niccolò Tribolo copied several of the features of the Villa di Castello, including a grotto, fountains, and a series of monumental stairways in his plans for the Boboli Gardens in Florence.
These gardens, like Villa di Castello, were built on a hillside, and featured a statue of Appennino, this one by Giambologna, multiple grottos, fountains, and hidden water jets to drench visitors.
The new garden, finished in 1564, featured a grotto with animals and figures made of pottery, a labyrinth, and flowerbeds laid along a central axis in geometric patterns.
She imported a family of skilled fountain-makers from Florence, led by Tommaso Francini, to build the Medici Fountain, with its grotto.