The Arsenal, the shipyard of the Venetian Republic, was the largest and busiest in the world until the end of the 17th century. From its founding in 1104, it was continuously expanded, until in its heyday, it employed as many as 16,000 workers.

 Closely guarded to preserve the secret production methods that enabled it to build a fully sea-ready ship in a single day, the Arsenal was accessible by one land and one sea approach only. 

So tight was its security that the Republic managed to keep its art of shipbuilding secret until about 1550. 

At its imposing land entrance is a Renaissance-style triumphal arch guarded by lions brought from Greece as booty after the reconquest of the Peloponnese in the 17th century. 

Of the two lions on the left, the larger one stood guard over the port of Piraeus, while its fellow stood on the road from Athens to Eleusis.