In prose the dative of place (chiefly place where) is used only of proper names: Πῡθοῖ at Pytho, Ἰσθμοῖ at the Isthmus, Σαλαμῖνι at Salamis, Ὀλυμπίᾱσι at Olympia, Ἀθήνησι at Athens (inscr.); especially with the names of Attic demes, as Φαληροῖ, Θορικοῖ, Μαραθῶνι. But ἐν Μαραθῶνι and ἐν Πλαταιαῖς occur. Some deme-names require ἐν, as ἐν Κοίλῃ.