One of the most beautiful outdoor wall fountains of the Renaissance was the tapping of the Acqua Vergine on the Via Flaminia. This grotto was built between 1550 and 1555 and was located below the second courtyard of the Villa Guilia. This was not far from the public fountain previously mentioned. The design of the fountain was of Vasari but was finished by Ammannati. Historically, this fountain has been called the "Fonte di Ammannati". The lowest point of the fountain was sunken, thus the name, "Fonte Bassa", which translates to mean low outdoor wall fountain. This fountain is not like many others as it is part of a wonderful architectural setting and serves a purposes rather than a simple stand alone fountain.
The additional 17th century engravings give it an original feel. The court of the water feature is made up of two levels. They are created with pilaster which are separated by indentations that vary in size. Once filled with ancient statues, known from the tellings of Ammannati's letter's to Marco Benavides. These statues have been removed for quite some time and now live in papl museums. The upper courtyard features an opening surrounded by a balustrade. Looking down upon a sunken court which features the F'onte Bassa. Small fountains were featured in these niches along with figurines that were set on a backdrop of fake rockwork and maidenhair ferns. The jets on these feed the outdoor wall fountain that encircled the pavement and included marbles. At the furthest end of the court, a semicirucluar exedra is featured with round and straight lines. Constructed out of white marble, four caryatids hold up the balustrade above them. These statues help to life up the outdoor wall fountains.
Standing at the entrance, the figures are further back within three niches. This gives the statues a dark backdrop and creates pop as the statues are made out of striking white marble. Behind each caryatid a similar figurine in mezzo rilievo is featured. With arched shape, grottos are covered with stucco rocaille and maidenhair fern. Two of these were once decorated with statues of putti that poured water into the wall waterfall fountain, coming out of the urns that were placed on their shoulders. A beautiful swan within a niche still remains. Three little boys, two of which in the center hold urns which they are emptying. People loved these statues and they were created by Ammannati. The charm of these statues can be seen in the chapels in San Pietro in Monotorio within the same time period.