Italy/Rome is an peninsula (a body of land surrounded by three sides of water). This will give the Romans more access to water and food and may even make an easier trade route. There is a negative effect too. If another state wants to trade but doesn't want to go on water, they have really no other option.
This is an island near the border of Rome. I would say this island is isolated. As you can see there are mountains (the dark green) mostly on the outer edge of the island. Of course they have a food source and have resources that they find in mountains, but really have no access to other sorts of living. they also border the edge of France.
The alps mountains served as a barrier and as a resource. one of them stood as tall as 14,692ft tall! When mountains are known for defense some can be to keep something in. There is also a forest at the bottom so they have a good supply of wood.
Bays are an example of something that separates the ocean life from an body of water so it is easier to get access to food and sometimes you can make crafts from shells.