Gateways are entrances from one space to another and as such, they are intended to function as specific transition points between two delineated spaces. This study is concerned with the manner in which the notion of transition is expressed architecturally and what implications this may have for textual analyses of Greek drama. Monumental architecture, including entryways, is invariably a practical form transformed beyond its practical function into something that is intended to perform the function of inspiring a particular state of mind in the viewer. A monumental gateway not only performs the practical function of articulating and controlling entrance and egress between two spaces, but it also prepares the viewer for the difference in experience from one space to another. This study concludes that the same principles that dictate the ideals of monumental gateways, as physical and metaphorical boundaries and vehicles of transition between spaces of contrasting character, are also prevalent in the staging and representation of space in Aeschylus' Agamemnon.