This gravity hill in Scotland is sure to stump anyone who looks at it. The road, located alongside a cliff, appears to be going uphill when it's really going downhill and vice versa.

Therefore, a car without its brakes on will look as if it's rolling uphill, pulled by some unseen force. For years, people thought that this unseen force was electricity, hence the hill's name.

In reality though, gravity hills are optical illusions, created when the horizon is obstructed. Without a horizon as a reference, it becomes hard for viewers to determine which way a hill is sloping.