Historically, the northern boundary of Yorkshire was the River Tees, the eastern boundary was theNorth Sea coast and the southern boundary was the Humber Estuary and River Don and River Sheaf. The western boundary meandered along the western slopes of the Pennine Hills to again meet the River Tees. It is bordered by several other historic counties in the form of County Durham, Lincolnshire, Nottinghamshire, Derbyshire, Cheshire, Lancashire and Westmorland. In Yorkshire there is a very close relationship between the major topographical areas and the geological period in which they were formed. The Pennine chain of Hills in the west is ofCarboniferous origin. The central vale is Permo-Triassic. The North York Moors in the north-east of the county are Jurassic in age while the Yorkshire Wolds to the south east are Cretaceous chalk uplands.
Yorkshire is drained by several rivers. In western and central Yorkshire the many rivers empty their waters into the River Ouse which reaches the North Sea via the Humber Estuary. The most northerly of the rivers in the Ouse system is the River Swale, which drains Swaledale before passing throughRichmond and meandering across the Vale of Mowbray. Next, draining Wensleydale, is the River Ure, which joins the Swale east of Boroughbridge. The River Nidd rises on the edge of theYorkshire Dales National Park and flows along Nidderdale before reaching the Vale of York.
The Ouse is the name given to the river after its confluence with the Ure at Ouse Gill Beck. TheRiver Wharfe, which drains Wharfedale, joins the Ouse upstream of Cawood. The Rivers Aireand Calder are more southerly contributors to the River Ouse and the most southerly Yorkshire tributary is the River Don, which flows northwards to join the main river at Goole. In the far north of the county the River Tees flows eastwards through Teesdale and empties its waters into the North Sea downstream of Middlesbrough. The smaller River Esk flows from west to east at the northern foot of the North York Moors to reach the sea at Whitby. The River Derwent rises on the North York Moors, flows south then westwards through the Vale of Pickering then turns south again to drain the eastern part of the Vale of York. It empties into the River Ouse at Barmby on the Marsh. To the east of the Yorkshire Wolds the River Hull flows southwards to join the Humber Estuary at Kingston upon Hull. The western Pennines are served by theRiver Ribble which drains westwards into the Irish Sea close to Lytham St Annes.
The countryside of Yorkshire has acquired the common nickname of God's Own County. In recent times, North Yorkshire has displaced Kent to take the title Garden of England according toThe Guardian. Yorkshire includes the North York Moors and Yorkshire Dales National Parks, and part of the Peak District National Park. Nidderdale and the Howardian Hills are designatedAreas of Outstanding Natural Beauty. Spurn Point, Flamborough Head and the coastal North York Moors are designated Heritage Coast areas, and are noted for their scenic views with rugged cliffs such as the jet cliffs at Whitby, the limestone cliffs at Filey and the chalk cliffs at Flamborough Head. Moor House - Upper Teesdale, most of which is part of the former North Riding of Yorkshire, is one of England's largest national nature reserves.
The Royal Society for the Protection of Birds runs nature reserves such as the one at Bempton Cliffs with coastal wildlife such as the Northern Gannet, Atlantic Puffin and Razorbill. Spurn Point is a narrow, 3 miles (4.8 km) long sand spit. It is a National Nature Reserve owned by the Yorkshire Wildlife Trust and is noted for its cyclical nature whereby the spit is destroyed and re-created approximately once every 250 years. There are seaside resorts in Yorkshire with sand beaches; Scarborough is Britain's oldest seaside resort dating back to the spa town-era in the 17th century, while Whitby has been voted as the United Kingdom's best beach, with a "postcard-perfect harbour"