These are suggestions for adding some unique creative terrain types. This is a list of creative terrains which currently do not appear to exist within Elemental, yet will hopefully be considered.
1} Rain Forests ~ This map location is similar to regular forests, yet due to the high amounts of rainfall during specific seasons the water level raises making it impossible to travel by land during these seasons. The very tall trees also prevent boat travel.
2} Flood Plains ~ The same as rain forests the flood plains become unusable during specific seasons due to either a nearby river flooding or high amounts of rainfall. During specific seasons food does grow more easily and in greater numbers... the Nile river can be a reference.
3} IceBergs ~ These are moving pieces ice which start in the cold parts of the map. As icebergs travel they might provide access to an island or river crossing otherwise unreachable by land or as a way to try escaping being hunted by another player/independent. The icebergs will eventually melt(unless magical), but should last many turns.
4} TarPits ~ As by definition this is an accumulation of natural tar which acts as a natural trap into which animals have fallen and sunk and had their bones preserved. I recall many prehistoric mentions how this type of terrain was large enough to cause problems for even dinosaurs. This terrain can be a natural barrier as well as provide a place for necromancers to obtain skelletal type creatures.
5} High Winds ~ This would be a type of barrier for only flying units in the skies. This barrier will allow map makers to create sections of map where ground units would be needed for exploring. I know winds are more weather related, but since most terrains provide disadvantages or barriers for ground units it seems important flying units should also have map sections where they have disadvantages or barriers.
6} Lava ~ I haven't seen lava as one of the types of terrain for Elemental. This terrain can provide a natural barrier for ground units. The lava can also be used by active volcanoes. Hopefully Elemental will have a few active volcanoes which have about a 3% chance of erupting each turn. Special boats immune to fire can be used for crossing such map sections which also have High Winds.
7} Mountain Peaks ~ Extremely high mountains which are impassable by both ground and flying units due to the high elevation and steep cliffs. This provides a natural barrier for all units.
8} Jungles ~ Extremely high amounts of dense vegetation and trees allowing only human sized units to travel. Also only human sized flying units would be able to land within this terrain. Such a unique terrain would provide several strategic options. Special plant creatures may also be found here, if plant creatures exist within Elemental.
9} Swamps ~ As by definition this is wet spongy land which is unfit for cultivation and diseases are more likely by most races. Structures on this land may sink(vanish) for many turns before rising again. Also although very very rare a structure from long long ago may raise out of the swamp.
9} Coral Reefs ~ Sections of the oceans and seas where there's higher amounts of seafood(fish) available. Any large ships have a 20% chance of being seriously damaged or sunk by the reefs when entering these waters.
10} Toxic Ponds ~ Deadly gases and acidic liquids are being released here from deep within the planet. It's common for diseased animals and bags of sewage to be catapulted into these locations since these areas have no other uses. Any ground travel here causes high chances of disease and will cause damage to any units crossing.