diff --git a/src/heightmap.cpp b/src/heightmap.cpp
--- a/src/heightmap.cpp
+++ b/src/heightmap.cpp
@@ -430,11 +430,24 @@ static bool ReadHeightMap(char *filename
 	}
 }
 
+/**
+ * Get the dimensions of a heightmap.
+ * @param filename to query
+ * @param x dimension x
+ * @param y dimension y
+ * @return Returns false if loading of the image failed.
+ */
 bool GetHeightmapDimensions(char *filename, uint *x, uint *y)
 {
 	return ReadHeightMap(filename, x, y, NULL);
 }
 
+/**
+ * Load a heightmap from file and change the map in his current dimensions
+ *  to a landscape representing the heightmap.
+ * It converts pixels to height. The brighter, the higher.
+ * @param filename of the heighmap file to be imported
+ */
 void LoadHeightmap(char *filename)
 {
 	uint x, y;
@@ -452,6 +465,10 @@ void LoadHeightmap(char *filename)
 	MarkWholeScreenDirty();
 }
 
+/**
+ * Make an empty world where all tiles are of height 'tile_height'.
+ * @param tile_height of the desired new empty world
+ */
 void FlatEmptyWorld(byte tile_height)
 {
 	int edge_distance = _settings_game.construction.freeform_edges ? 0 : 2;