How did geography impact Sparta’s military tactics during the Peloponnesian War?

Sparta did not have to worry about an invasion because it was located on top of a mountain.
Athens was located on an island, forcing the Spartans to use many ships to transport its army.
The stronghold of the Delian League was on Delos, requiring Sparta to have a strong navy.
Athens's location made it difficult to attack, forcing the Spartans to destroy farmland and crops.