Cumbria is a county in the North West of England, boasting some of the most beautiful scenery in the United Kingdom. It contains the Lake District National Park, about one quarter of which is owned and managed by the National Trust. It also contains a small part of the Yorkshire Dales National Park. Cumbria was formed in 1974 from the former counties of Cumberland and Westmorland. Covering over 6,808 square kilometres, Cumbria incorporates the famously scenic Lake District which includes Scafell Pike, England's highest mountain at 978 metres. Other notable mountains include Helvellyn, Coniston Old Man and Skiddaw. Cumbria and the Lake District is also home to England's longest lake, Windermere (17 kilometres in length). The region was popularised in the early 19th Century by the 'Lake Poets' (Wordsworth, Coleridge and Southey). Principal urban centres are Whitehaven and Workington (both are ports), Penrith, Keswick, Kendal, Carlisle and Barrow-in-Furness. The main western railway to Scotland passes through Penrith and Carlisle, and a major English motorway (the M6) runs from the south side of Birmingham up as far as Carlisle. The population of Cumbria is approximately 491,000.