The Lighthouse is an extremely important early game building that is relatively cheap. Its Food production can help boost early cities, and maintain a strong Population growth as they occupy more ocean tiles; its Housing also helps to that end, increasing maximum population capacity.
It also gives Great Admiral points and extra combat experience, which is extremely useful when training fleets and armadas.
Historical Context Edit
The sea is a dangerous place, filled with shoals, shallows, reefs, and rocks just waiting to bring the unwary ship to grief. And the weary crew might have a difficult time finding safe harbor. So, in antiquity, not long after men began sailing, signal fires were lit to guide the ship away from danger to port; since such signal fires would be even more visible if elevated, “lighthouses” began to be built by the first seafaring civilizations on promontories. The most famous of the ancient ones: the Pharos at Alexandria, of course, which guided ships into what was once the busiest seaport in the world. For two thousand years since, lighthouses were built wherever there was a need for sailors not to drown and cargos not to be lost. Stone, wood, and brick have given way to steel and concrete construction, and fire has given way to arc lamps, but the principle remains the same.