Ogyges

Ogyges, a Boeotian autochthon, the legendary first king of Thebes, which is called at times Ogygia, in whose reign a flood, called the Ogygian after him, inundated the land, though some accounts make it occur in Attica.

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)

O'Groat's House, John * Ogygia
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Oersted, Hans Christian
Oesel
Offa's Dyke
Offenbach, Jacques
Offertory
Ofterdingen, Heinrich von
Ogham
Oglethorpe, James Edward
Ogowe`
O'Groat's House, John
Ogyges
Ogygia
Ohio
Ohio River
Ohm, Georg Simon
Ohnet, Georges
Oil City
Oka
Oken, Lorenz
Okhotsk, Sea of
Oklahoma