Many years ago i worked with a chap who was deep into Lay Lines and the like and i didn't believe any of it, so one lunchtime he proposed an experiment, just down the road from where we worked was a church (Nyetimber for the locals to me), now before we went he sent me out of his office and he drew a map of the church and yard which he photocopied, on one copy he marked all of the lines he could remember on it, once done he locked it in his desk, the other copy being for me.
When we arrived at the church he gave me the other photocopy of the map he had drawn (minus his lay lines) and a set of divining rods, he explained their use and then to make things fair he stayed some distance from me so as to not influence me or my findings, then he just asked me to walk around and mark on the map where the rods crossed or swung outwards, so after about 30 - 40 minutes, we really did have to get back to the office, i kept the map with the lines i had drawn on it on my person so he could not tamper with it.
Once back at the office we went into his office and he unlocked his desk drawer and removed his copy of the map and laid it flat on the desk, i laid my copy alongside and was stunned as they were nigh on identical, I had missed some, but those i had found as indicated by the rods were near as damn it smack on exact, even to the point of laying one map on top of the other and then putting them up against the window so we could see both sets of drawn on lines, resulted in identical markings.
I was gobsmacked, it was a pretty convincing argument and although I'm not into happy clappy type stuff, from that day onward i have felt that there is something to the lay line phenonium.
One other thing we did with dowsing rods was looking for water at a site we were redeveloping into ponds, the site had a seasonal stream, but we wanted to see if there was permanent water source like a spring, the guy in charge had already been up and walked round with dowsing rods and had identified an area of interest, when the rest of us turned up to work, he got us to walk around the area individually and out of the sight of the others and asked each of us to note any changes as indicated by the rods, but not to say anything, so we all had a walk round and then gathered back by the vans in the car park, we then all went as a group and placed a stick on the sites of interest, all of us, put the sticks in near as damnit the exact same area.
Armed with this info we tracked the digger over and dug a gert big hole looking for water, did we find it, nope, nothing, all we found was a dirty great hole that went as deep as a 27 ton machine could dig, ok it could have a been a lay line again, but it was interesting nevertheless that all four of us there had the rods cross in exactly the same spot. What is really interesting though is just last year at the same site they installed a borehole, its 60m deep and hits a pocket of water, unbeknown to them or me at the time the borehole is within a few meters of where we had the rods indicate water all those years ago, no wonder we never found it with the machine.
Has to be something to it, what that is i don't know, but it sure is interesting.