Most Iapetian geological features are named after characters and locations in the Old French epic poem The Song of Roland, specifically the English translation by Dorothy L. Sayers.
Named impact craters are:
A mons , pl. montes , is a mountain.
There is one named Iapetian regio (area of distinct albedo difference), Cassini:
There are two named Iapetian terrae (large 'land' masses).
The adjectival form of Roncevaux is Roncesvallian.