Author Terry Brooks, best known for his Sword of Shanarra series, wrote the Magic Kingdom of Landover series as a humorous alternative to his more serious fare. The Black Unicorn is book #2, and continues the story of Ben Holiday, a Chicago lawyer who buys a literal magic kingdom after losing his wife and daughter in a car accident.
The setting of The Black Unicorn is the magical realm of Landover, where many worlds are connected. Landover is a stereotypical fantasy world, with many typical fantasy creatures and species living in it, including goblins, trolls, dragons, witches, and fairies (Wikipedia). This gives it the features of a larger world in a small space; Landover is not very large, but since it is a portal to other worlds, it is often used by travellers from other realms. Each species living on Landover has its own ruler, theoretically answerable to the King, although no one until Ben has ruled for twenty years. Landover is surrounded by "fairy mists," which are both the mechanism of portal to other realms and the home of the Fairies who created Landover. The kingdom is rural and most of its inhabitants survive on hunting and agriculture. In a larger sense, it resembles a fantasy version of a medieval serfdom, with a ruling elite overseeing workers, but Landover is more pragmatic and most of its inhabitants are dismissive of Ben as their King.