Ahill is alandform that extends above the surrounding terrain. It often has a distinctsummit, and is usually applied to peaks which are above elevation compared to the relative landmass, though not as prominent asmountains. Hills fall under the category ofslope landforms.
The distinction between a hill and amountain is unclear and largely subjective, but a hill is universally considered to be not as tall, or assteep as a mountain.
Geographers historically regarded mountains as hills greater than 1,000 feet (304.8 meters) abovesea level. In contrast,hillwalkers have tended to regard mountains as peaks 2,000 feet (610 m) above sea level. TheOxford English Dictionary also suggests a limit of 2,000 feet (610 m) and Whittow[1] states "Some authorities regard eminences above 600 m (1,969 ft) as mountains, those below being referred to as hills." Today, a mountain is usually defined in the UK and Ireland as any summit at least 2,000 feet or 610 meters high,[2][3][4][5][6] while the UK government'sCountryside and Rights of Way Act 2000 defined mountainous areas (for the purposes of open access legislation) as areas above 600 meters (1,969 feet).[7] Some definitions include atopographical prominence requirement, typically 100 feet (30.5 m) or 500 feet (152.4 m).[4] In practice, mountains inScotland are frequently referred to as "hills" no matter what their height, as reflected in names such as theCuillin Hills and theTorridon Hills. In Wales, the distinction is more a term of land use and appearance and has nothing to do with height.
For a while, the US defined a mountain as being 1,000 feet (304.8 m) or more tall. Any similar landform lower than this height was considered a hill. TheUnited States Geological Survey, however, has concluded that these terms do not in fact have technical definitions in the US.[9]
Ahillock is a small hill. Other words include knoll and (in Scotland, Northern Ireland and northern England) its variant, knowe.[11] Artificial hills may be referred to by a variety of technical names, includingmound andtumulus.
Various names may be used to describe types of hills, based on appearance and method of formation. Many such names originated in one geographical region to describe a type of hill formation particular to that region, though the names are often adopted bygeologists and used in a wider geographical context. These include:
Many settlements were originally built on hills, either to avoid floods (particularly if they were near a large body of water), for defense (since they offer a good view of the surrounding land and require would-be attackers to fight uphill), or to avoid densely forested areas. For example,Ancient Rome wasbuilt on seven hills, helping to protect it from invaders.
Some settlements, particularly in the Middle East, are located on artificial hills consisting of debris (particularlymudbricks) that has accumulated over many generations. Such a location is known as a "tell".[13]
InNorthern Europe, many ancient monuments are sited in heaps.[clarification needed] Some of these are defensive structures (such as thehillforts of theIron Age), but others appear to have hardly any significance. In Britain, many churches at the tops of hills are thought to have been built on the sites of earlier pagan holy places. TheWashington National Cathedral inWashington, D.C. has followed this tradition and was built on the highest hill in that city.[citation needed]
Some cities' hills are culturally significant in their foundation, defense, and history. In addition to Rome, hills have played a prominent role in the history ofSan Francisco, withits hills being central tothe city's fog and civil engineering projects today famous as tourist attractions such as thecable cars andLombard Street.[14]
Hills provide important advantages to an army that controls their heights, giving them an elevated view and firing position and forcing an opposing army to charge uphill to attack afort or other position. They may also conceal forces behind them, allowing a force to lie in wait on the crest of a hill, using that crest for cover, and firing on unsuspecting attackers as they broach the hilltop. As a result, conventional military strategies often demand possession of high ground.
TheGreat Wall of China is an enduring example of hilltop fortification. It was built on hilltops to help defend against invaders from the north, such asMongols.
Hillwalking is aBritish English term for a form ofhiking which involves the ascent of hills. The activity is usually distinguished frommountaineering as it does not involve ropes or technically difficultrock climbing, although the terms mountain and hill are often used interchangeably in Britain. Hillwalking is popular in hilly areas such as the EnglishPeak District and theScottish Highlands. Many hills are categorized according to relative height or other criteria and feature on lists named after mountaineers, such asMunros (Scotland) andWainwrights (England). Specific activities such as "peak bagging" (or "Munro bagging") involve climbing hills on these lists with the aim of eventually climbing every hill on the list.
Cooper's Hill Cheese-Rolling and Wake is an annual event in theWest Country ofEngland which involves rolling a wheel ofcheese down a hill. Contestants stand at the top and chase the wheel of cheese to the bottom. The winner, the one who catches the cheese, gets to keep the wheel of cheese as a prize.[citation needed]
Cross country running courses may include hills which can add diversity and challenge to those courses.[15]
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