We've arrived, time to Split.

Leo Valdez making a pun about the city and having to split into two groups

Split is a city in Croatia situated in the Mediterranean Basin on the eastern shores of the Adriatic Sea, centered around the ancient Roman Palace of the Emperor Diocletian and its bay and port. 

The Heroes of Olympus

The House of Hades

120px-THO Jason

Jason Grace, who suggested changing course to Croatia.

Jason Grace has a vision of Rachel Elizabeth Dare and Grover Underwood delivering a message to the Romans. After the vision is over Jason orders Leo Valdez to change course for Croatia the location of the palace and tomb of Diocletian. Jason and Nico di Angelo then go to retrieve Diocletian's scepter encountering Favonius, the Roman god of the west wind, and Cupid, the Roman god of love, who are the guardians of Diocletian's Scepter Cupid manages to make a Nico reveal his romantic feelings towards Percy Jackson in exchange for the scepter. Jason then has a dream showing him that Reyna Avila Ramírez-Arellano is on her way to Split and will visit Diocletian's tomb. He then leaves a note for Reyna telling her where to go from the tomb to find the Argo II.

Locations (CHB)
Magical Locations: Aeolia | Camp Half-Blood | Camp Jupiter | Cave of Trophonius | C.C.'s Spa and Resort | Daedalus' Workshop | Lotus Hotel and Casino | Mount Othrys | Ogygia | Olympus | Pan's Cave | Sea of Monsters | The Labyrinth | Tartarus | Underworld | Waystation
Cities, States, and Towns: Alaska | Bar Harbor | Bologna | Chicago | Detroit | Gila Claw | Indianapolis | Jamestown | Montauk | New Mexico | New York City | Palm Springs | Quebec | San Francisco | Dalmatia | Vancouver | Venice | Westport
Other Locations: Apennine Mountains | Aunty Em's Gnome Emporium | Carlsbad Caverns | Crusty's Water Bed Palace | Empire State Building | Gateway Arch | Grand Canyon | Greece | Hoover Dam | Italy | Junkyard of the Gods | Mount Diablo | Mount Etna | Mount Saint Helens | Mount Tamalpais | Pikes Peak | Polyphemus' Island | ROFL | Rome | Triple G Ranch | U.S.A. | Waterland