The Allies in Italy attacked the new German defensive line--the Gothic Line (Massa-Rimini fortifications). It was constructed by Kesselring in the Northern Appenines Mountains (August 1944). It was the most heavily fortified position the German prepared in Italy.
After the fall of Rome (June 4, 1944), the Germans retired to this new defensive line, a heavily fortified belt some 16 km deep, extending from south of La Spezia on the west coast, through the Apuan mountains and the Apennine passes, and then down the Foglia valley to the Adriatic Sea between Pesaro and Cattolica.
source:
http://www.histclo.com/essay/war/ww2...2i-gothic.html
and:
http://members.tripod.com/~aries46/gemmoliv.htm