The excavators have divided Ostia into five regions, numbered I to V. Within the regions blocks (insulae) and individual buildings have been distinguished, numbered as follows: (region) I, (block) I, (building) 1, etcetera.

The five regions can be accessed in two ways. If you are not yet very familiar with the topography of Ostia, we suggest that you discover the city using the text menu. If you know your way around, then you may prefer to use the clickable plans. Please note however, that some buildings and structures are not recognized easily on the plans. Others are not clickable at all, for example buildings in unexcavated areas, found during recent geophysical research.

Please note that the photos made by Klaus Heese and Daniel González Acuña are available at high resolution, together with many additional photos, in the Photo galleries.