What walls did the Athenians call long? why were they called that?

In ancient Greece, fortifications that served to connect a city located from the sea with its port or ports were called Long Walls. The walls in Athens were considered the longest known. This defensive structure allowed the inhabitants of the city to withstand the siege without losing access to the sea. In the event of a siege, Athens became an impregnable fortress because the possibility of cutting off the city from the supply of food by sea was lost.