As it stands now, Adventure techs' values depreciate if other civs research them first. By that, I mean that goodie huts are first-come-first-served, and if another civ explores them all first, you get nothing. I don't like this.
I would like to see goody huts and heroes be made civ-specific (invisible and/or un-explorable by other civs). Here's why:
1. Fun: Everybody loves a goody hut. I hate when they get explored by another civ, right in front of your face! If I want to experience the MOST FUN part of the game, I HAVE to research Adventure techs early and often to stay ahead of the other thieving stinking civs.
2. Pacing: It would help slow down the frantic exploration rush. Instead of needing to beat other players to clear the map, exploration would be more about venturing out when the reward outweighs the risk. It gives the player a lever to control the pace based on where they are in the game, and whether they're ready for the next set of challenges.
3. Research motivations: It makes sense that when you delve more deeply into the world (read: research an Adventure Tech) when you need/want/can handle it, not just to stay ahead of the other civs. It makes for more interesting choices: do I try to become stronger from within by developing my other techs and cities, or without by exploring? Do I want to unleash powerful monsters now, or wait till I'm stronger? Do I need more to do now, or am I good?
4. Lore: The lore talks about the world being hostile, and I think that this mechanism would shift the focus from completely civ-vs.-civ to civ-vs.-world.
3. Fits Tech description: The Adventure techs say that by researching them you are better able to detect the unique opportunities in the world. It doesn't make sense that you would be able to "see" them because another civ researched them. Not everyone in the world should know about every "secret" lair or "hidden" cache.
4. Variety: Having civ-owned huts opens the opportunity for civ-specific quests. Lots of neat things can be done here to help further differentiate the various civs and add flavor.
5. Balance: Now, whoever researches the Adventure Techs first gets all the gravy, leaving only the scraps for the other civs.
6. Civ-interactions: What if a great gleaming goodie hut appears in your neighbors territory? Instead of being like "oh, well, they'll get it before I can", you can either a) sign a open borders agreement (or some temporary exploration visa), 
invade them, c) sell the knowledge of the location d)wait until some later date.
Thoughts?
