Archaeological excavations on the foundations of the Rose and the Globe in the late 20th century showed that all the London theatres had individual differences, but their common function necessitated a similar general plan. The public theatres were three stories high, and built around an open space at the centre. Usually polygonal in plan to give an overall rounded effect, although the Red Bull and the first Fortune were square. The three levels of inward-facing galleries overlooked the open centre, into which jutted the stage: essentially a platform surrounded on three sides by the audience. The rear side was restricted for the entrances and exits of the actors and seating for the musicians. The upper level behind the stage could be used as a balcony, as in "Romeo and Juliet" and "Antony and Cleopatra", or as a position from which an actor could harangue a crowd, as in "Julius Caesar".