From the middle of the 11th century, Amalfi's center of shipbuilding, custom houses, and warehouses was the Arsenale, today the only (partially) preserved medieval shipyard in southern Italy. Ships and galleys up to 80 feet long, equipped with up to 120 oars, were built at this largest arsenal of any medieval maritime republic. Two large Gothic halls here now host the Museo della Bussola e del Ducato Marinaro di Amalfi (Museum of the Compass and Maritime Duchy of Amalfi) with exhibitions and artifacts from Amalfi's medieval period, including paintings, ancient coins, banners, and jeweled costumes. The highlight is the original 66-chapter draft of the code of the Tavole Amalfitane, the sea laws and customs of the ancient republic, used throughout the Italian Mediterranean from the 13th to the 16th century. The Tavole established everything from prices for boat hires to procedures to be followed in case of a shipwreck. Long one of the treasures of the Imperial Library of Vienna, the draft was returned to Amalfi after more than 500 years. Ten of the arsenal's original 22 stone piers remain; the others were destroyed by storms and changes in the sea level on this ever-active coast.