Derbyshire is a county in the East Midlands of England. A substantial portion of the Peak District National Park lies within Derbyshire, containing the southern extremity of the Pennine range of hills which extend into the north of the county. The county contains part of the National Forest, and borders on Greater Manchester to the northwest, West Yorkshire to the north, South Yorkshire to the northeast, Nottinghamshire to the east, Leicestershire to the southeast, Staffordshire to the west and southwest and Cheshire also to the west. Kinder Scout, at 636 metres (2,087 ft), is the highest point in the county, whilst Trent Meadows, where the River Trent leaves Derbyshire, is its lowest point at 27 metres (89 ft). The River Derwentis the county's longest river at 66 miles (106 km), and runs roughly north to south through the county. In 2003 the Ordnance Survey placed Church Flatts Farm at Coton in the Elms (near Swadlincote) as the furthest point from the sea in Great Britain.The city of Derby is a unitary authority area, but remains part of the ceremonial county of Derbyshire. The non-metropolitan county contains 30 towns with between 10,000 and 100,000 inhabitants. There is a large amount of sparsely populated agricultural upland: 75% of the population live in 25% of the area.The area that is now Derbyshire was first visited, probably briefly, by humans 200,000 years ago during the Aveley interglacialas evidenced by a Middle Paleolithic Acheulean hand axe found near Hopton. Further occupation came with the Upper Paleolithic and Neolithic periods of the Stone Age when Mesolithic hunter gatherers roamed the hilly tundra. Evidence of these nomadic tribes has been found in limestone caves located on the Nottinghamshire border. Deposits left in the caves date the occupancy at around 12,000 to 7,000 BCE.Because of its central location in England, and its altitude range from 27 metres in the south to 636 metres in the north, Derbyshire contains many species at the edge of their UK distribution ranges. Some species with a predominantly northern British distribution are at the southern limit of their range, whilst others with a more southern distribution are at their northern limit in Derbyshire. As climate change progresses, a number of sensitive species are now being seen to be either expanding or contracting their range as a result.A number of specialist organisations protect, promote and monitor records of individual animal groups across Derbyshire. The main ones are Derbyshire Ornithological Society; Derbyshire Mammal Group; Derbyshire Bat Group, Derbyshire Amphibian and Reptile Group, and the Derbyshire & Nottingham Entomological Society. All maintain databases of wildlife sightings, whilst some such as the Derbyshire Ornithological Society provide alerts of rare sightings on their websites or social media pages, and also publish major works describing the status and distribution of species.The county of Derbyshire has many attractions for both tourists and local people. The county offers Peak District scenery such as Mam Tor and Kinder Scout, and more metropolitan attractions such as Bakewell, Buxton and Derby. Local places of interest include Bolsover Castle, Castleton, Chatsworth House, National Tramway Museum at Crich, Peak Rail steam railway, Midland Railway steam railway, Dovedale, Haddon Hall, the Heights of Abraham and Matlock Bath.