A gravity hill, also known as a magnetic hill (and sometimes a mystery hill or a gravity road), is a place where the layout of the surrounding land produces a car left out of gear rolling uphill due to gravity.
A gravity hill, also known as a magnetic hill (and sometimes a mystery hill or a gravity road), is a place where the layout of the surrounding land produces the optical illusion that a very slight downhill slope appears to be an uphill slope. Thus, a car left out of gear will appear to be rolling uphill due to gravity.