I think that we have discovered a new approach to teaching this subject.We look at a map and find fun places to go. We then try to estimate the distance it is away from us and try to decide if we are capable of traveling that far. (Some choices are eliminated at this point.) Then if a place is within our distance abilities then we have to consider the elevation of the location in relationship to our current elevation. If it is much higher then it will be hard getting there, but it will be easier to come back. On the other hand... if it is easy getting there then for the return trip when we are tired from being gone all day then it is all uphill and very difficult. One route may include several smaller hills, but another may include one straight hill that is direct to where we need to go. The weather plays a large part as well, but I'll go into that on the appropriate page. :) My kids have picked several locations, like the local lake for swimming, that took much preparing for. There is plenty of incentive for the kids to work hard with a good attitude when it is their trip that we are going on. We can look ahead at the beautiful mountains and learn the names of the peaks as well as the river names. The kids ask questions and we all learn together as we study to find out the answers together. 

This is why unschooling works so well. The kids are teachable, and their curiosity is at its peak.