Hill Facts



  • Hills often have a shallow S-shaped slope. Geologists call this kind of slope `convexo-concave’ because there is a short rounded convex section at the top, and a long dish-shaped concave slope lower down.
  • Hill slopes become gentler as they are worn away, because the top is worn away faster. This is called decline.
  • Retreat is where hill slopes stay equally steep, but are simply worn back.
  • Replacement is where hill slopes wear back, with gentler sections becoming longer and steeper sections shorter.
  • Decline may take place in damp places; retreat happens in dry places.
  • A hill is an elevation of the Earth’s surface with a distinct summit.
  • One definition of a hill is high ground up to 307 m high. Above that height it is a mountain.
  • Mountains are solid rock; hills can be solid rock or piles of debris built up by glaciers or the wind.
  • Hills that are solid rock are either very old, having been worn down from mountains over millions of years, or they are made from soft sediments that were low hills.
  • In moist climates hills are often rounded by weathering and by water running over the land.
  • As solid rock is weathered, the hill is covered in a layer of debris called regolith. This material either creeps slowly downhill or slumps suddenly in landslides.