This encyclopaedia, compiled around 530 AD,is more or less the Byzantine Encyclopaedia Britannica of the ancient world. It lists some 3,600 names of places, mountains, lakes, rivers, waters and peoples, explaining their origins and derivations. The founding legends and wealth of cultural historical information contained in it make it a source text for polis research; in addition, it is a treasure trove of quotations andliterary fragments.