there are many clues that indicate that aquitanian was spoken in the pyrenees, at least as far east as val d'aran. place-names that end in ‑os, ‑osse, ‑ons, ‑ost and ‑oz are considered to be of aquitanian origin, such as the place-name biscarrosse, which is directly related to the city of biscarrués (note the navarro-aragonese phonetic change) south of the pyrenees. "biscar" (modern basque spelling: "bizkar") means "ridge-line". such suffixes in place-names are ubiquitous in the east of navarre and in aragon, with the classical medieval ‑os > ‑ues occurring in stressed syllables, pointing to a language continuum on both sides of the pyrenees. this strong formal element can be traced on either side of the mountain range as far west as an imaginary line roughly stretching from pamplona to bayonne (compare bardos/bardoze, ossès/ortzaize, briscous/beskoitze), where it ceases to appear.