How does Shakespeare create a vivid world within Macbeth?

Shakespeare's plays are full of vivid worlds; look no further than the imaginative forest outside Athens in A Midsummer Night's Dream, or the fairy-tale setting of Belmont in A Merchant of Venice. Like these plays, Macbeth features a vivid world that is at once both believable and fantastic. One of the main ways that Shakespeare creates this vivid world is by including the three witches, the Weird Sisters. 

By beginning his play with the strange spectacle of the Weird Sisters on a deserted heath, Shakespeare immediately tells the audience or reader that the world of Macbeth includes supernatural powers. Although, it is worth noting that the audience at the time would have probably perceived witches as a very real threat. Indeed, the Weird Sisters can be seen as an example of the inexplicable supernatural forces that lurk on the fringes of rational civilization. In that case, though Macbeth is largely a play about political ambition, tyranny, and civil war, it also involves an exploration of fantastical, seemingly magical elements and how they apparently govern human life. Therefore, though most of the events in Macbeth are largely explainable with human reason, Shakespeare also creates a world that is vivid because it allows for the inclusion (through the Weird Sisters) of the irrational, the magical, and the downright spooky.