The Arsenal is the fortified shipyard of Braavos.
The Arsenal is located at the entrance to Braavos's lagoon, just beyond the Titan. It sits upon a knob of rock, fortified with stone battlements and bristling with scorpions, trebuchets, and spitfires.
The Arsenal houses the defense fleet of Braavos and is the center of shipbuilding for the city. Along its shores are innumerable quays, docks, and wooden sheds holding galleys. The Arsenal's war galleys are all constructed with the same design, allowing shipbuilders to work on separate parts at the same time and thereby create a galley in a single day.
During the Daughters' War, Lord Alyn Velaryon defeated a Braavosi fleet in the Stepstones, sinking more than thirty galleys and capturing six galleys and eleven cogs. When Lord Manfryd Mooton negotiated with the Sealord to prevent war after Lord Alyn's attack, the Sealord showed the famed Arsenal to the regent and boasted that Braavos had already replaced their lost ships.
A Feast for Crows
—writings of Yandel