How to write a descriptive essay about a city (Rome)? How to organize the essay?

I am a university student of English and one of my assignments requires me to write an essay on the topic Discovering...(a city/country/town).

So, my topic is Discovering Rome.

I think this topic falls under the category of descriptive essays, but I don't understand in which order I should describe the city (the spatial order). Can somebody please help?

The word limit is 600-750

OK so I am new to answering questions here but if I were you I would start by describing Rome by the senses. Talk about how beautiful it is, the way it smells, or the feeling of walking on the same stones as great emperors may have walked upon(the last was referring to the coliseum). Rome is an ancient city. If i were you I would relate your experiences in Rome to the history of the place. However, it all depends on what you're interested in. Good luck!