The nymph's spring and the kingdom's counsel

Egeria was a nymph in Roman mythology, who served as a counselor, lover, and eventually wife to King Numa Pompilius. After King Numa’s death, Egeria turned into tears, creating a spring, which became her sacred place. This nymphaeum, located in Parco regionale dell'Appia antica, near Via Appia and Via Latina, is one of the oldest and most important examples of a nymphaeum in Rome antique.

The water from the spring was exclusively used by Vestal virgins. The nymphaeum was renovated in the 2nd century AD by Erode Attico, who inherited the surrounding villa. Inside the Nymphaeum, there is a statue of Egeria placed in a niched, surrounded by green and white marble walls and green porfido floor, with mosaic inserts. The original spring, one of a dozen that flow into the Almone river, was redirected into large basins, one of which was known as Lacus Salutaris.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons