This is by far my favorite Julio Claudian coin which shows
C CAESAR AVG GERMANICVS PM TR POT/PIETAS SC – Pietas sitting left, pouring from a patera.
DIVO AVG SC – Caligula veiled and draped as a priest, sacrificing from a patera over an altar, with two attendants and the Temple of Augustus in the background.
Mint: Rome (37AD)
Caligula served as priest of the cult of Augustus, the rituals of which are depicted on the reverse.
From CNG: This issue commemorates Gaius Caligula’s dedication of the Temple of the Divus Augustus and the young emperor’s sense of pietas. Many of Caligula’s issues were meant to emphasize his connections to the Augustan family and good Roman values. The PIETAS beneath the figure of the emperor drives home the point that he is fulfilling his duty by dedicating the temple to his great-grandfather. Construction of the Temple of the Divus Augustus began under Tiberius and, perhaps, under the direction of Livia herself, in the general area behind the Basilica Julia (though the actual site remains unknown), and was subsequently dedicated by Caligula. Mention of this temple again appears in Suetonius’ Life of Gaius (Caligula) when that emperor, believing himself a god, incorporated the building’s roof in his skybridge from the imperial residence on the Palatine to the Temple of Jupiter Optimus Maximus on the Capitoline. cngcoins.com
Note the die-cutters art and craftmanship on a coin nearly 2,000 years old. The coin gives us a look at the architecture and the way the religious ceremony was carried out. Look at the garlanded festooned columns and the statues of Victory Acroteria, statues of Romulus and Aeneas at roofline.