Which preposition to use with eleusis

by Occurrences 1%

And the tomb of Iolaos, and Eleusis by the sea, are just witnesses to his honours.

in Occurrences 1%

ELEUSINIAN MYSTERIES, rites, initiation into which, as religiously conducive to the making of good men and good citizens, was compulsory on every free-born Athenian, celebrated annually at Eleusis in honour of Demeter and Persephone, and which lasted nine days.

Which preposition to use with  eleusis