Caldonia is the cursed continent to the south of Arcadia. 1509 years ago it was frozen over in the same horrific event that created the canals of Arcadia.
It was first visited in Misscliks: Seaborn: Chapter 4 Episode 5 Part 2. The party of hero were looking for a broken mountain near a lake & bay, where hid a 1500 year old abandoned temple to Velmontarious to find a relic to entrap the soul of a Dragon.
It was shown again in Frozen Frontier Episode 01: A Caldonian Welcome. In 1509, High Princess Sela of the kingdom of Drekis launched an expedition to Caldonia in hopes of recovering the treasures of a lost civilization. The first outpost was Fort Wikk. The Second was Swampside.
The Seaborn visit to Caldonia takes place a few months into the Frozen Frontier campaigns, but the two groups do no cross paths.