Green marsh

Green marsh is a tile in the Factorio decoration category used to represent a marshy, green terrain type; it functions as decorative terrain and is intended primarily for visual variation and map aesthetics rather than as a gameplay mechanic. As a decoration tile, Green marsh is placed and removed like other terrain tiles and does not confer special production, pollution, or interaction effects beyond its appearance. If only the name and category are available, Green marsh should be understood simply as a decorative tile asset within the game's terrain system.