Map Making in the free game C-evo can be researched very early and may have immediate benefits as well as leading to longer-term gains, particularly related to water. The earliest benefit is usually the addition of trade points to tiles containing rivers. Map Making leads to Seafaring, which allows the building of Harbors, adding food points to coastal water tiles The other value is enabling a nation to build "The Lighthouse", a Wonder that adds material yield to coastal water tiles, though it may eventually be obsoleted.