I have never tried dowsing but I have felt and followed "lines of power" for the want of a better phrase.
Maryrrf, Glastonbury has still got some feeling left but I think it has changed for the worse since the 60s when I first started going there, The Tor has a spiral line clockwise but I have seen bands of "mist" one morning early as I was going home on the road past the tor. It was at about 4:30 in the week after the summer equinox.
dave