A gravity or magnetic hill is a place where a slight downhill slope appears to be an uphill slope due to the layout of the surrounding land, thus creating an optical illusion that water flows uphill or a car left out of gear will roll uphill, among others.
There is a handful of such hill around the world, one of which is located in Jeju Island, South Korea. The Mysterious Road, also known as Dokkaebi Road, has earned its name, as objects and liquid appear to roll and flow up the hill instead of down, hence going against the rule of gravity.
This natural wonder was discovered by a taxi driver in 1980 who was giving a driving tour to a newlywed couple around this area.
Some cheeky ones claim that this is due to those spirits roaming the area pushing the objects upward. In reality, such image of gravity defiance is an optical illusion rendered by the seemingly high surroundings.