What region whose name means "Estate of the Salt Chamber" has Austria's third largest lake?
Attersee (lake):  It is Austria's third largest lake by area, surpassed only by Lake Constance and Lake Neusiedl, which, however, both extend beyond national borders. Salzkammergut:  The name "Salzkammergut" literally means "Estate of the Salt Chamber" and derives from the Imperial Salt Chamber, the authority charged with running the precious salt mines of the Habsburg Monarchy.
Salzkammergut