The denarius (plural: denarii) is a type of Roman currency used by Roman demigods at Camp Jupiter and the citizens of New Rome, It was also used in Ancient Rome. Denarii are analogous to the Greek currency of drachmas, used in Camp Half-Blood. Denarii might be made of gold or silver.
When Frank, Percy, and Coach Hedge arrive at the aquarium, they have three denarii, which they use to pay Keto for VIP treatment, but it turns out to be a trap set by Phorcys and Keto to trap the two demigods and make them part of their exhibit.
- In the past, the Romans debased the denarius to fund their empire. They began to use the double denarius instead.
- The dinar, used as currency in a few Middle Eastern and Eastern European countries today, derives its name from the denarius.
- Denarius is the Roman counterpart of the Golden drachma and Red Gold.