Thalassar is the capital city of the Kingdom of Vyrndal. Silverpine is located in Vyrndal and is west of Thalassar. The road that leads east from Silverpine and all the way to the map edge leads to Thalassar. Thalassar isn't currently reachable as a playable area, but the NPC that leave Silverpine to visit the capital do walk all the way over there and back.
Poor, Mirel walks it nearly every night/morning.
Edit: Rosalyn might mention a friend she visits in the capital, Isolde. She's in lore as a fennec fox and is energetic. She isn't a current NPC that we know of.