The city of Pompei was shaped irregularly because it was built on a prehistoric lava flow. The excavation brought to light the city walls; they are 2 miles in circumference and they enclose an area of about 163 acres (66 hectares). Seven city gates have been excavated. The main street running in a south-north direction was the Via Stabiana, through which was passing the traffic from the sea. This street was crossed by two other streets.

The public buildings are for the most part grouped in three areas: the Forum, the Triangular Forum and the Amphitheatre and Palaestra.

1. The Forum was the centre of the city’s religious, economic and municipal life; it was a large rectangular area, surrounded by two-story colonnaded portico. The Forum was surrounded by temples, a large provision market, a meeting place of the city council and then the offices of the magistrates. A large basilica, surrounded on four sides by a corridor, is the most architecturally significant building; it was a covered exchange and as a place for the administration of justice.

2. The Triangular Forum, where there was a Doric temple, a theatre, a palaestra (sport ground) and a small covered theatre and, not far, the Amphitheatre, meant for circensian games and bloody fights of men and beasts. Baths were scattered throughout the tow and many are in luxurious private homes.

3. But more significant than the public buildings, are the hundreds of private homes. These are unique, for only at Pompei is it possible to trace the history of Italic and Roman domestic architecture for at least four centuries. The earliest houses date from the first Samnite period (4th-3rd century BC). The house of the Surgeon is the best-known example of the early atrium house built during this period.
The most luxurious houses were built the following two centuries, when increased trade and cultural contacts resulted in the introduction of Hellenistic refinements.

The House of the Faun occupies an entire city block and has two atria (chief rooms), four triclinia (dining rooms) and two large peristyle gardens.

Many of the houses from this Samnite period were decorated with elaborate floor mosaics. The House of the Silver Wedding, with its imposing high-columned atrium, outstands for its handsome banquet hall and the exedra, beautifully decorated, which served as a schoolroom for children of the family.

Fewer houses were built during the Roman period. They are usually less imposing, with lower atria, but with more elaborate decoration.

There are also numerous small homes throughout the city; many of them are shop houses.