The Docks is where shipments are sent and recieved. At the building, current shipments can be viewed.
Unlike other buildings, the Docks can not be built or sold; it is present from the start of the estate.
The Docks can be leveled in either Workplaces or Efficiency. Increasing the level of Workplaces adds 1 additional workplace to the building. Increasing the level of Efficiency decreases the shipping costs by 5% per level.