Hey athlete, regarding your questions:
1) Dungeon: Nothing happens if you move on it. Only a little icon will show up in the bottom bar (where you have the fortify-icons etc.). Clicking on it will have your unit exploring the dungeon. That is basically like opening a hut, though I think there are more "bad" outcomes possible (unit disappearing, some barbs spawning etc. edit: is more risky but also more rewarding I guess).
2) Fort: You probably will not be able to move there as there should be at least one barb standing on it (I guess kind of an archer with 6 defence). The fort will continously spawn barbs, but I do not know how often, probably something like every 5 or 10 rounds. If you can kill the barbs guarding the fort, you can raze it, ending this threat.
Oh, and beware, scouts and warriors in the early game are dieing easily.
1) Dungeon: Nothing happens if you move on it. Only a little icon will show up in the bottom bar (where you have the fortify-icons etc.). Clicking on it will have your unit exploring the dungeon. That is basically like opening a hut, though I think there are more "bad" outcomes possible (unit disappearing, some barbs spawning etc. edit: is more risky but also more rewarding I guess).
2) Fort: You probably will not be able to move there as there should be at least one barb standing on it (I guess kind of an archer with 6 defence). The fort will continously spawn barbs, but I do not know how often, probably something like every 5 or 10 rounds. If you can kill the barbs guarding the fort, you can raze it, ending this threat.
Oh, and beware, scouts and warriors in the early game are dieing easily.