Eberron - Return of the Lich Queen
The city of Wroat is the political seat of power for the nation of Breland housing both the royal family and the royal parliamant. The great walled city is built on opposing banks of the Howling River just before it flows into the Dagger River. The city also occupies a manmade island that sits in the middle of the river and it is here that Brokenblade Castle as well as The Citadel can be found.
For more info: Eberron Wiki