why are there instances of water and objects going uphill?

Question: why are there instances of water and objects going uphill?
- Keywords:
  objects,
  uphill
Asked by Robert to Cheryl, Christina, Daniel, George, Ivy on 24 Jan 2017.
- Cheryl Andisi answered on 24 Jan 2017:
  
  @ Robert, Hi,
  These hills are what are called magnetic hills or gravity hills. These hills, found in many parts of the world, from our very own Kyamwilu hills in Machakos hills in India, Canada, USA etc.
  Gravity hills create an optical illusion making a slight downhill slope appear to be an uphill slope. This would explain why a drop of water would appear to be moving against gravity, or a car will appear to move up the hill.

Question: why are there instances of water and objects going uphill?