I’ve always wondered how the Greek and Roman mythologies can overlap in culture, and Riordan gives a great insight into how this could happen in his modern take on these mythologies.

The Lost Hero by Rick Riordan (The Heroes of Olympus #1)
The Son of Neptune by Rick Riordan (The Heroes of Olympus #2)
The Mark of Athena by Rick Riordan (The Heroes of Olympus #3)
The House of Hades by Rick Riordan (The Heroes of Olympus #4)
The Blood of Olympus by Rick Riordan (The Heroes of Olympus #5)