Princes Street Gardens are two adjacent public parks in the centre of Edinburgh, Scotland, lying in the shadow of Edinburgh Castle. The Gardens were created in the 1820s following the long draining of the Nor Loch and building of the New Town, beginning in the 1760s. The loch, situated on the north side of the town, was originally an artificial creation forming part of its medieval defences and made expansion northwards difficult. The water was habitually polluted from sewage draining downhill from the Old Town. The gardens run along the south side of Princes Street and are divided by The Mound, on which the National Gallery of Scotland and the Royal Scottish Academy buildings are located. East Princes Street Gardens run from The Mound to Waverley Bridge, and cover . The larger West Princes Street Gardens cover and extend to the adjacent churches of St. John's and St. Cuthbert's, near Lothian Road in the west. In 1846 the railway was built in the valley to connect the Edinburgh-Glasgow line at Haymarket with the new northern terminus of the North British line from Berwick-upon-Tweed at Waverley Station. The Gardens are the best known parks in Edinburgh, having the highest awareness and visitor figures for both residents and visitors to the city. Railway In 1846, the Edinburgh and Glasgow Railway company constructed a sunken railway line along the southern edge of the Gardens to join its Haymarket terminus to a new General Station adjoining the North British Railway Company's North Bridge terminus (both stations later renamed Waverley Station). This involved constructing the Haymarket Tunnel (comprising separate north and south tunnels), 910 metres long, between the western end of the gardens and Haymarket Station. A shorter tunnel (again comprising two separate tunnels) was also dug through The Mound which separated the East and West Gardens. East Princes Street Gardens History East Princes Street Gardens originated after a dispute between Edinburgh Corporation (town council) and the early New Town proprietors, among whom was the philosopher David Hume who resided in St. David Street, a side street off Princes Street. In 1771 the council acquired the land as part of the First New Town development. It began feuing ground on the south side of Princes Street (on the site of the current Balmoral Hotel and Waverley Market) for the building of houses and workshops for a coach-builder and a furniture-maker. After a failed petition to