Duke Girolamo Mattei, who had seen Barberini's splendid Triton water fountain, decided that he wanted Gian Lorenzo Bernini to make him something similar for his Caelian Hill villa Celimontana in 1648. According to the only piece of evidence from an engraving by Venturini , Bernini placed a similar Triton at the end of one of the avenues, sitting on three or four scaly sea monsters whose necks and heads stretched out from a mass of rocks half-submerged in the low, rustic circular pool. The triton lashed his tails and, holding his conch in his right hand, blew water into the air. The engraving shows two porters at the entrance to this avenue, each holding a little barrel with water falling into a small basin identical in design to the one around the Triton fountain.

A second fountain to note, also in villa Mattei and also built around 1648, was the one called "Olympus." The inspiration for this fountain is the rustic Eagle Fountain in the Vatican. This fountain had three gigantic dolphins, all in a row, using their tails to hold up the usual open shell from which the enormously outsized eagle is drinking.

The third vanished fountain is the one carved between 1653 and 1671 for Cardinal Anton Barberino near the Bastions. This fountain, while having very little water and the finest of sprays, featured a woman who, after she had washed her hair, wrings it out so that as much water comes out as the fountain can provide to put action into the figure.

Lastly, another fountain by Bernini portrays a backing onto the boundary wall of a fairly narrow courtyard garden which looks more like a well and has been completely abandoned. It was built for an individual called Paolo Strada, at the house on his estate on the road Paul V opened up at the foot of the Quirinale Hill. At that time the road was called "Strada Nuova." Today it is Via della Panetteria and the house is number 15. Here we find a repetition of all Bernini’s favorite themes such as the two bad-tempered tritons breathlessly blowing water from their conches, two dolphins with their tails in the air holding up the usual open shell, and the whole surrounded by the customary rocky border.