Explorer is one of the two rewards you can choose after you have upgraded a level 1 city to level 2 (the other being Workshop). It spawns an explorer who shows you some of the tiles around you. Every tile it explores gives 5 points. These explorers can also be found in ruins. Sailing gives the Explorer the ability to walk on water, and Navigation lets it walk on ocean tiles. Explorers change in color based on the tribe that used them.