Stepping away from mainland Schiehallion, these are the northeastern and southwestern continents of Galedon, the homeland of the humans, and Bro'kuhn the current home of the giants.
The rough size of Galedon is about 1.8 million square miles. Each of the three "horns" was home to the Caldonii tribes of (east to west) Carvetti - a friendly lake land, seafaring people of good neighborly relations with the Caldonii (middle) and the more remote and standoffish Gothos. The central Caldonii are modeled after highland Scots and the Carvetti are like the Irish and Cumbrians. The Gothos were a hearty Viking like people who mostly kept their own council and were not overly concerned with the affairs of the outside world. Going way way back to their aboriginal homeland, Farnoria (coming next time), the Gothos are most like the very first humans to wander and take to the sea. To give an idea of what the terrain and climate of Galedon is like, picture a mix of Alaska and the Scottish Highlands.
This land of giants takes it's name from literally being broken off from the mainland and heaved farther out into the sea. The islands of the east coast make the waters between them and the reaching southwestern fingers of mainland Schiehallion quite treacherous. This is compounded by the fact that giants in this world are notorious rock chuckers who love nothing better than splintering a ship on the crags with a well thrown boulder. I'm still working out why the giant(s) tore off a corner of the continent and cast it away. Perhaps they were tired of the persecution they suffered at the hands of other races.
If I can come up with a good name/translation for "one who rends asunder" that could be the giant who flung away the piece to make his own hiding place across the waves. It took all he had to do it, but he wasn't able to distance himself enough. So now he sits exhausted on the shores of Bro'kuhn staring back at the home he can never return to. Both lands are his, but he may only claim a small scrap of what was once a grand paradise. I may incorporate a story about the smaller islands being created by the descendants of the cast away giant who had a boulder throwing contest to test their strength/pay homage to their forefather. Over time the channel became choked with more and more islands from these games.
I love how ideas like that just come to me as I'm writing. Giants, yes they're big and mean and will huck rocks at passersby....but why? There has to be a reason for their angst and aggression. Even if their victims don't understand that maybe in the past the giants themselves were driven away by stoning, it lends a sadness to the inner character of the race that only the reader gets to bear witness to. Poor "monsters". Bro'kuhn is about a quarter the size of mainland Schiehallion, or approximately 750,000 square miles.