This is the 169th most frequent Greek word.
αθήνα
Athens (capital of Greece).
Here, 'Αθήνα' refers to the city of Athens as a proper noun.
Η Αθήνα είναι η πρωτεύουσα της Ελλάδας.
Athens is the capital of Greece.
In this sentence, 'Αθήνα' is used to indicate the destination of travel, referring to the same city.
Θα πάμε στην Αθήνα το Σαββατοκύριακο.
We will go to Athens this weekend.
Here, 'Αθήνα' is used in the possessive form to discuss an attribute related to the city.