Places
like Roca di Papa in Italy or Karpacz Gorny in Poland are known for
so-called "gravitational anomalies". Only precise
measurements could clarify what these phenomena are really about. The
most obvious explanation is an optical illusion that makes you think
that things are going uphill, although in reality they are going
downhill. The fact that a nearby mountain changes the direction of
gravity is practically impossible due to the much too small mass in
relation to the earth.