How did Rome's geography affect their culture?

There is an old saying: "all roads lead to Rome." At the height of the Roman Empire, this was a simple fact. Because of the location of Rome within Italy—set far back from the coast and without any viable sea ports to use for trade or military bases—the Romans focused upon land power and upon the building of roads more intensely than any previous civilization. As a result, the entirety of the Roman Empire was characterized by the presence of long, straight, reliable roads which enabled Roman soldiers to march more easily than they could have across waste ground and enabled the transportation of goods within the Empire. Because of this excellent road network, Rome became the nexus of the Mediterranean region in terms of trade, despite the fact that it had no access to traditional sea channels. 
This quirk of geography also influenced the way in which the Romans typically fought. In the early days of the Empire, they had almost no naval power. Because of this, their foot soldiers were unusually well-trained because the might of the Empire was focused on building up their land forces. This gave the Romans the advantage over many of the soldiers in the countries they invaded. 
While Rome lacks a sea port, there were other elements of its geography that contributed to its strength as a defensible military outpost and as a thriving city for people to live in. Rome is known as the 'city of seven hills'; its elevated position meant that it was possible to see attackers coming for miles around, which increased Rome's military advantage. Meanwhile, the soil in the city was generally well-suited for farming, while the climate was suitable for growing many of the crops that formed the basis of the Roman diet. As such, Rome could be besieged without being starved out.