Bristol ) is a major city and county in South West England with a population of 463,400. The wider district has the 10th-largest population in England. The urban area population of 724,000 is the 8th-largest in the UK. The city lies between Gloucestershire to the north and Somerset to the south. South Wales lies across the Severn estuary. Iron Age hill forts and Roman villas were built near the confluence of the rivers Frome and Avon, and around the beginning of the 11th century, the settlement was known as Brycgstow . Bristol received a royal charter in 1155 and was historically divided between Gloucestershire and Somerset until 1373 when it became a county of itself. From the 13th to the 18th century, Bristol was among the top three English cities, after London, in tax receipts. Bristol was surpassed by the rapid rise of Birmingham, Manchester and Liverpool in the Industrial Revolution. Bristol was a starting place for early voyages of exploration to the New World. On a ship out of Bristol in 1497 John Cabot, a Venetian, became the first European to land on mainland North America. In 1499 William Weston, a Bristol merchant, was the first Englishman to lead an exploration to North America. At the height of the Bristol slave trade, from 1700 to 1807, more than 2,000 slave ships carried an estimated 500,000 people from Africa to slavery in the Americas. The Port of Bristol has since moved from Bristol Harbour in the city centre to the Severn Estuary at Avonmouth and Royal Portbury Dock. Bristol's modern economy is built on the creative media, electronics and aerospace industries, and the city-centre docks have been redeveloped as centres of heritage and culture. The city has the largest circulating community currency in the UK; the Bristol pound, which is pegged to the Pound sterling. The city has two universities, the University of Bristol and the University of the West of England, and a variety of artistic and sporting organisations and venues including the Royal West of England Academy, the Arnolfini, Spike Island, Ashton Gate and the Memorial Stadium. It is connected to London and other major UK cities by road and rail, and to the world by sea and air: road, by the M5 and M4 ; rail, via Bristol Temple Meads and Bristol Parkway mainline rail stations; and Bristol Airport. One of the UK's most popular tourist destinations, Bristol was selected in 2009 as one of the world's top ten cities by international travel publishers Dorling Kindersley in their Eyewitness series of travel guides. The Sunday Times named it as the best city in Britain in which to live in 2014 and 2017, and Bristol also won the EU's European Green Capital Award in 2015.