Mons lapideus sive terdona (unknown)

Mons lapideus sive terdona ("Stone Mountain, or Terdona") is a mountain marked on a single Sfera map (Con3, map 1a, 16v), on the shore of what might be meant as the Caspian Sea. The geography is confused due to a misunderstanding of the Armenian mountains as a body of water, which was then transmitted through a particular group of manuscripts, including this one.) We have found no likely references to any such names in the general area of Armenia, Persia, or western Asia, but it's worth noting that next to this mountain on the map there is a note reading "Here Saints Simon and Thaddeus were martyred" (an event that took place in Persia according to Jacopo da Varagine's Golden Legend). See also Bavulti, Tradenti, Ben cista.