Sitting at the highest and most exposed point of the ridge, the Temple of Juno was built around 450 BC as a near-twin to the Temple of Concordia, sharing its general proportions and its six-by-thirteen column arrangement. Thirty-four columns once ran the full peristyle; a good number still stand, tapering and swelling with the same entasis technique used at Concordia.
The temple still bears reddish scorch marks on its stone, scarring from the Carthaginian sack of Akragas in 406 BC, a visible reminder of the single worst event in the ancient city's history. It was later restored under Roman rule, its original terracotta roof replaced with one of marble, angled more steeply on the eastern side.
Its name is actually a historical mix-up. "Juno" (or Hera Lacinia) comes from a misreading of the Roman writer Pliny the Elder, who was describing an entirely different Temple of Hera, one near Crotone on the Italian mainland, hundreds of kilometres away. The mistake was made centuries ago by early antiquarians and simply stuck, the same way "Concordia" did next door. What the temple was actually dedicated to in antiquity is unknown.