A gravity hill is a phenomenon in which your car appears to roll uphill. 
You can only observe it in a car – removed enough from your surroundings for the trick to work 
yet close enough to believe.
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Sometimes they’re called magnetic hills or mystery hills. 
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“The most important factor contributing to the illusion is a completely or mostly obstructed horizon. Without a horizon, it becomes difficult to judge the slope of a surface as a reliable reference is missing.” 
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What else is a mystery hill? 
How much depends on an obscured horizon?
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Related:
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“The term ostension is also used by those who study folklore and urban legends to indicate real-life happenings that parallel the events told in pre-existing and well-established legends and lore.”
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The ostension of a wedding. 
The ostension that is marriage. 
The gravity hill of love.







References:
‍https://en.m.wikipedia.org/wiki/Gravity_hill
‍https://en.m.wikipedia.org/wiki/Ostension