Fantasy Triumph allows players to build any army they wish. And give them whatever topography they deem appropriate, including Dense Topography.
Dense Topography doesn't exist in historical battles. Dense topography represents armies whose home turf is way way more dense with terrain than even hilly and forest terrain in the real world. Instead of the map being default of clear open terrain, with patches of terrain placed on the map, you have the reverse -- default of some difficult terrain type, with patches of open.
See the Fantasy Triumph rules for detailed description. What you get here is an aid to gamers who are interested in building such terrain for a Fantasy Triumph army. How do you do it? What might it look like? There are many solutions; what I've put here is just some of my own examples, to help Fantasy Triumph players in getting ideas of how to approach Dense Topography.
So far I've got images up for two "Underground" Dense Topo examples -- one natural caverns, and one for a dungeon-style Khazad-dum-like Dwarven Underground Stronghold (whether infested by Goblins taking over, or its original Dwarven population). The third page is a Green Hell / Dense Jungle page with some pics of my Lizardman army using it. Upcoming I've got a Science Fiction Dense Topo that is intended for fighting urban battles or huge battleship boarding actions, but no pictures of that up yet.