Nea Smyrni exists because of a catastrophe. When the Greeks of Smyrna were driven across the Aegean in 1922, tens of thousands washed up in Athens, and one wave of them built a new quarter on the southern edge and named it after the city they'd lost. A century on it's one of the most liveable parts of Athens — and the great square at its centre is the proof.
Start in the plateia, vast and café-ringed, and take a table on the edge. Best in the evening, when the volta fills the square and the light softens. Walk the flank to Agia Fotini, named for the lost Smyrna cathedral, then past Estia Neas Smyrnis, the centre that keeps the Asia-Minor memory — the music, the recipes — alive.
Then out into the leafy grid: low blocks, bitter-orange trees, no monuments, just the everyday city. Cut down to the Alsos, the pine grove with its open-air theatre, where families gather as the heat drops. Loop back along Omirou and the streets feeding the square, where the patisseries run one after another. Order a Constantinople-style sweet, then the tram back to the metro.