"Just because a city is built in a coastal region doesn't guarantee that the city is readily accessible by ship. In order for a port city to establish a steady trade, fishing, or other shipping industry, the city must have a harbor. A harbor is a protected body of water that opens into an ocean or lake that shelters ships from waves and high winds. Although some coastal cities are established in areas where a natural harbor exists, most seaports are forced either to improve the existing natural harbor, or to build a man-made harbor to shelter ships and provide channels deep enough to accommodate large vessels."
In the city screen press the following icon to start Harbor construction:
- ↑ Cost depends on Game Speed. Quick: 53 , Epic: 120 , Marathon: 240 .
- ↑ This special ability affects every version of the game, but appears only in .
- ↑ This special ability affects only in and .
- ^ 4,0 4,1 This special ability affects only in .
- ↑ This special ability affects only in and and appears only in .