Praeneste
An ancient city of central Italy, where, Macrobius says, June was long called Junonius.
Today: Palestrina, Lazio, Italy
Where the months got their names
Macrobius, Saturnalia 1.12–14 (early fifth century CE), in the edition of Franz Eyssenhardt (Leipzig, 1893) · early fifth century CE; the dialogue is set in the 380s
Iunius Maium sequitur aut ex parte populi, ut supra diximus, nominatus aut, ut Cingius arbitratur, quod Iunonius apud Latinos ante uocitatus, diuque apud Aricinos Praenestinosque hac appelatione in fastos relatus sit adeo ut, sicut Nisus in commentariis fastorum dicit apud maiores quoque nostros haec appelatio mensis diu manserit, sed post detritis quibusdam litteris ex Iunonio Iunius dictus sit. nam et aedes Iunoni Monetae Kalend. Iuniis dedicata est.
June follows May. It was named either after a part of the people, as I said above, or, as Cingius judges, because the Latins once called it Iunonius [after Juno]. The people of Aricia and Praeneste long kept this name in their calendars. As Nisus says in his notes on the calendar, our ancestors too kept this name of the month for a long time, but later some letters wore away and Iunonius became Iunius. Indeed, the temple of Juno Moneta was dedicated on the first of June.