Detail of the floor of the Rustic Fountain

The Rustic Fountain dates back to the time of Cardinal d'Este and was rearranged during the brief pontificate of Gregory XV Ludovisi (1621-1623). The fountain took on its current appearance at the end of the 19th century, when many layers of limestone were deposited, but it is still recognizable under the thick concretions that surround it. In addition, the pope had his coat of arms represented in the floor mosaic located in front of the fountain.