From Halopedia, the Halo wiki
Castiglione is the capital city of Escala III.
In March 2558, Thomas Lasky along with Naiya Ray met with Petra Janecek in Castiglione to disuss investigating a spy in the UNSC.
Lasky and Janecek at the city's harbor.
Lasky and Petra discussing the UNSC traitor.