Something like that, yes =) Instead of just using A* to find a route around any obstacle, I'm working on different heuristic methods depending on obstacle type. Mountains are simple; despite of their irregular shape you can treat them as regular polygons, and then just go from point to point. But rivers are entirely different; they are easiest to cross on shallow fords, so my algorithm first looks for suitable fords and then picks the best one. And that was the tricky part =) For a moment I thought that maybe I should just drop my heuristics and go for A* as that should always find the route. But after some work with pen and paper I guess I got my heuristic rules working... For the fun of it, I'll post a picture to illustrate the river puzzle. The picture is here: http://www.enormouselk.com/?q=erkkasblog/images/river-puzzle