About 10 years ago, when my father-in-law was beginning to fail from cancer, he started telling me all the things he felt I needed to know about their land for when my wife inherited it from them. Things such as water cutoffs, how to drive their tractor, he made me go up in the attic to look at the heating/AC unit so I would feel comfortable doing it later, etc.
One of the things he also instructed me to do was to walk down a certain ravine on the land and find the small spring that comes out of the ground and feel how cold the water is. He told me that he probably should have built a pond down there at some point in his life. That is where our 2 acre pond is now located.