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.
Göde-Stiftung > FAQs > More about gravity (FAQs) > Gravitational anomalies: Are there places on our planet where the gravitational potential pulls a body (e.g. a car) up a mountain against all expectations?