When can you utilize land mark terrain?

I'm new to this. I didn't see any documentation on the landmark terrain files, but it's clear that they're being used since they're in so many terrain mods. They don't show up in the Civ Editor, so I can't understand how any bonuses might apply when they're used versus standard terrain.

Since I'm really into Nature, and want diversity of plants and terrain on the map, I'd like to include them if someone has an explanation, or a way to activate the amount of bonuses or restrictions for them.

My map is extremely large as most of the initial cities are actually homesteads or homes. It has way more terrain than most maps, and so diversity of resources leads to something closer to realism. It's more akin to a huge state map versus the world even though it's using the largest allowable dimensions (256 x 256 as far as I know).

I'd like to have some mountains that can be colonies and/or cities (homesteads), so that they offer a defensive bonus, but limit the amount of bonuses in terms of agriculture. It'll mean a proper amount of grassland or plains are around them.

Is there a way to designate one time only terrain as a special LM and so it only appears there. Thus unique terrain might occur and offer something special to whomever holds it.

One of the civilizations is Mother Nature herself, and she's centralized on the map, but I'd like to restict the other civilizations from getting to her too fast. That way she can take over or have several city/homesteads under her control to spawn units from. I was thinking maybe I could utilize Land Marked terrain for this purpose.

Landmark terrain can be edited in the Terrain tab of the Civ3Editor under the normal terrain tile. You can apply different food, shield, movement costs, defense bonuses, can cause disease etc. They are located on the right side of the rules window of the normal terrain tile. I think you can also change the graphics of the landmark terrain but by default they look the same as their normal terrain tile.

Most of the terrain tiles have a LM tile linked with it and you can apply different bonuses to each of them. Under the terrain tab you can also edit what terrain can have cities, are impassable/impassable by wheeled units and also can change allow colonies, forts etc.

Thanks for the swift reply. Hopefully I'll be able to easily achieve altering it such that certain terrain can be upgraded easily.

I realize you can't mix and match landmark terrain easily due to palette differences (like yellow or green balance), which is too bad because you can't just load a terrain in Gimp and easily adjust the tint. That is unless someone knows a simple way to do it?

Because the workers chop down trees to free up shields for projects, I guess what I'll do is use plant resources. In this way, say oak trees are located in a square, then acorns and hardwood will be available to allow a building to harvest the nutmeats as a food source (a major one in history due to fat and protein within them) as well as one of the primary hardwoods for building materials. Likewise maple trees might be a resource rather than a landmark terrain tile, and so a maple syrup operation can exist to provide a necessary food source. Sugar beets, sorghum, apiaries producing honey were the alternative ways.

Back on topic, the terrain could be so much MORE to alter the defensive results. Say you have both the regular rivers AND wide rivers for example. Some could be easily spanned with bridges and perhaps others couldn't.

EDIT: Since my WROL Plague Edition concentrated on contagion as a persistent catastrophic post-apocalyptic event, one of the things I'd like to do is designate some terrain other than swamps as causing the Plague. What I wanted to do was have former metropolitan areas to be designated plague zones. Not only would they cause the contagion, but with so many deaths occuring, and in the absence of Rule of Law, and no sanitation, starvation, and physicians, then the problem would be 10x times worse. Maybe I could only use one landmark terrain that looks like special ruins of those cities, but it's UNLIKE regular ruins that disappear when built upon? They're persistent terrain that would be Dead Zones. On the other hand, many valuable caches of materials would be found there, leading many to be tempted to chance acquiring them through the establishment of colonies. You'd have a chance of illness from entering the area, but with a potentially high payoff in certain trade items (like ammunition or certain weapon types) and without them it might be decades before you could create those units yourself?

A designated Landmark Terrain like that would be within the Fog of War, and this means that the AI will spawn infected barbarians within it, and they will in turn attack those colonies of caches as well as workers and end up traveling on the roads back to the various settlements too.

EDIT2: Pounder made some water railroads and altered some landmark terrain such that navigateable channels of water could allow a means by which certain water craft could traverse them. I'm hoping to learn more about this process because this would add so much to the game even if it works imperfectly.