In fact, Shakespeare didn't know what a balcony was.
The word 'balcony' never appears in Shakespeare's play. There's only one problem: There is no balcony scene in Romeo and Juliet. Colloquially known as 'the balcony scene,' it contains Romeo and Juliet's most quoted lines, which are so closely associated with the balcony that they're frequently repeated (often incorrectly and in a hammy style) by non-actors who seize upon any real-life balcony, porch, landing, or veranda to reenact the moment.
It's perhaps the most famous scene in all of English literature: Juliet stands on her balcony with Romeo in the garden below, star-crossed lovers meeting by moonlight.