Oiasso,
Oiasona or
Oiarso was a
Basque Roman town located on the left bank of the
Bidasoa estuary in the
Bay of Biscay (current
Basque Country, in Spanish territory). Archaeological evidence unearthed recently pinpoints the core area of Oiasso in the old quarter of
Irun (
Gipuzkoa) by the Spanish-French border, where harbour and bath remains have been discovered. However, two other focuses in
Cape Higuer and hermitage Ama Xantalen (
necropolis and
mausoleum) point to a wider complex outside the main nucleus.