Definition of the hill function, the origin of the coordinate system

terminology - Is there a standard definition of a hill? - Earth Science Stack Exchange

Silbury Hill - Wikipedia

What is the difference between a large hill and a 'pass'? - Quora

Difference between hill and mountain

What is a Mountain? - Geography Realm

American English at State - Have you ever called someone over the hill? Be careful using this idiom (over the hill)! It can sometimes be used as a joke, but some people

Over The Hill: the Meaning of the Useful Idiom Over The Hill • 7ESL

Susan Hill Quote: “Of all human activities, apart from the procreation of children, gardening is the most optimistic and hopeful. The garde”

Zion, History, Significance, Map, & Facts

The hills we choose to die on - Battle of California