Imperia is born from the merger of two existing cities, Oneglia and Porto Maurizio, and their territories, historically and geographically distinct.
Oneglia, to the east, is the most extensive part of the city, extends on the short alluvial plain on the left of the mouth of the River Impero, surrounds Piazza Dante, from which some of the main streets of the city begin. It has historically constituted the industrial center of the city, mainly due to the production of olive oil and pasta. Oneglia is more commercially oriented than Porto Maurizio and the center of Oneglia is characterized by traces of the Piedmontese architecture (it is evident in the arcades of Via Roma and Piazza San Carlo di Torino), heritage of the period when it was part of the territories of Savoy and the Kingdom of Sardinia.
Porto Maurizio to the west of the River Impero (which gave name to the city), is situated on a promontory jutting into the sea on the left of the mouth of the River Caramagna, and expands on the foreland. It has a predominantly residential and tourist destination. It is intricate and colorful, rich of narrow streets, small lanes and fine mansions.
The land behind the city, at the center of the Italian Riviera, has an topography characterized by short valleys, placed perpendicular to the coast and sloping evenly, where they developed many villages that have managed to save intact or quasi their original structure.
Olive growing, introduced around theXII century, left a deep mark in the history of the Imperia territory, as well as, centuries later, they cultivated the flowers and did tourism. Olives growing on terraced hills (known in local dialect fasce) with characteristic dry stone walls are the dominant feature of the landscape.