In contrast to the businesslike setting of Venice, Belmont represents romance and possesses almost a fantasy-type atmosphere. This is a strange concept to modern audiences, because we often think of Venice as an extremely romantic city, but this portrayal of the city would not have been foreign to Shakespeare's audience. During his time, Venice was a cosmopolitan trading center for much of Europe--a business hub. So, when Shakespeare portrays scenes and characters in Venice, notice that most of his writing carries a business tone. For example, Shylock--a shrewd businessman--rarely speaks in verse. His prose lines lament business losses or the way he is treated by other businessmen. Another example of this is that the trial takes place in Venice because the city abides by the letter of the law, rather than the spirit of it.
In order to understand Belmont, the reader must be able to contrast it with Venice. Belmont is full of music, love, riddles, and poetry. Shakepeare's lines which are spoken in Belmont or by key Belmont characters are lyrical. Likewise, at the end of the play, all of the couples are in Belmont. They have left Venice or have always lived in Belmont (i.e., Portia). Finally, Belmont clears up all the problems between the couples or seems to sweep away the mundane cares of the world. Bassanio and Gratiano give up their wives entrusted rings in Venice, but it is Belmont where the plot is unraveled, and the men work to regain their wives' hearts. Moreover, a troubled Antonio goes to Belmont after the courtroom ordeal, perhaps to escape a city which makes his heart heavy.
Shakespeare is using the standard practice of the day in giving people and places meaningful names. Belmont means literally beautiful mountain (bel-mont) and represents what is most virtuous and true in the world. You could say that Belmont is a fairytale place, hardly real with its strange story of the casket competition. All this is in contrast to Venice, which is where all the grubby, commercial, real-life part of the play takes place.
Bear in mind that the London of Shakespeare’s day was one of the world’s busiest and most cosmopolitan cities. For a man coming from a small market town like Stratford-on-Avon, London/Venice must have been quite a shock.