Rocheste is the city outside of Colhen that is accessible through the portal beside Brynn's Laboratory.
The Royal Army originates from Rocheste and is where Tieve, Clodagh, and Marrec's dear friend, Keaghan resides as a high ranking member of the Royal Army. Gwynn and Ellis often mention going to Rocheste throughout the main storyline.
A Dragon can occasionally be seen roosting on one of Rocheste's Towers.
Spoiler: Episode 10 After Tieve and Keaghan become Morrighan and Cichol, respectively, the entire city acts as if they have never known Keaghan, and greets the player as if they've never met. Blawynn also says that the Royal Army dispatched a team yet they have no memory of it, believing that everyone's minds were forcibly erased somehow.
List of NPCs