One of the 5 gateways to the Ghetto was located at the end of Via della Reginella. This street is typical of the area and ends in Piazza Mattei, named after an important family of the Middle Ages.
They controlled the Isola Tiberina, the island in the Tiber River, and so had hegemony over the entire left bank. This family used the site and the material of the Theater of Balbus to construct the first of a series of buildings, known in the mid 16th century as the Isola Mattei.
Buildings such as these indicated great economic power deriving from trade and commerce. The family used the experience and ability of the Jews to construct these buildings and, in return, offered them whatever protection they needed.
One of Rome's most elegant fountains is located in the center of this piazza, the Fontana delle Tartarughe, the Tortoise Fountain
. The fountain itself was designed by Giocomo della Porta at the end of the 16th century, but it was Bernini who added the tortoises in 1658.