Piraeus has a long recorded history, dating back to ancient Greece. The city was founded in the early 5th century BC, when plans to make it the new port of Athens were implemented: A prototype harbour was constructed, which resulted in concentrating in one location all the import and transit trade of Athens, along with the navy's base.[3] During the Golden Age of Athens, the Long Walls were constructed to fortify the route from the main settlement to the port (Piraeus). During the classical period, the naval base in Piraeus had 372 trireme shipsheds.[4] Beginning in the 3rd century B.C., Piraeus went into a period of cumulative decline. However, it began growing once again in the 19th century, after Athens was made the capital of Greece. Today, Piraeus is a large city, bustling with activity, and an integral part of Athens. It is a huge marine and commercial-industrial centre, and home to Greece’s largest harbour.