Not so glorious as some other European arcades (e.g. Milan's Galleria Vittorio Emmanuele) but the Books' Arcade (you can see the sign in greek), just beside the Arsakeion building hosts some of the most intellectual events in the city. All major Greek publishers have premises here while there is a specially designed gallery on the basement level for exhibitions, presentations and events, all associated with books.
Info taken from Athens Info Guide
See the exact place on the map