Minister of Scotland. A few small sections remained undeveloped at the time. In 1885 an unbuilt section of Queen Street (an open garden until that time), north of St Andrew Square, provided the site for the Scottish National Portrait Gallery. To the north-west, north of Charlotte Square, the land was part of the Earl of Moray's estate and a long-running boundary dispute with the Moray Estate. caused delay in development. A section of Glenfinlas Street at the north-west corner of Charlotte Square was not completed until 1990 while the western end of Queen Street, north of Charlotte Square, has never been developed. The New Town was envisaged as a mainly residential suburb with a number of professional offices of domestic layout. It had few planned retail ground floors, however it did not take long for the commercial potential of the site to be realised. Shops were soon opened on Princes Street, and during the 19th century the majority of the townhouses on that street were replaced with larger commercial buildings. Occasional piecemeal redevelopment continues to this day, though most of Queen Street and Thistle Street, and large sections of George Street, Hanover, Frederick and Castle Streets, are still lined with their original late 18th century buildings. Northern, or Second, New Town and extensions After 1800, the success of the first New Town led to grander schemes. The 'Northern New Town' (now usually called the Second New Town) aimed to extend Edinburgh from the north of Queen Street Gardens towards the Water of Leith, with extensions to the east and west. These developments took place mostly between 1800–1830. Initial designs by William Sibbald followed the original grid orientation of Craig’s First New Town, with entire streets being built as one construction. Building continued on an extended Hanover Street, called Dundas Street and, beyond Great King Street, Pitt Street (later renamed to Dundas Street in the 1960s), almost 1 km north towards the Water of Leith at Canonmills, where Bellevue Crescent would eventually mark the most northern extent of the New Town project. Streets were laid out either side with Great King Street the central avenue terminated by Drummond Place to the east and Royal Circus to the west. Northumberland Street and Cumberland Street were lesser streets to the south and north respectively. Heriot Row and Abercromby Place, both one-sided streets at the southern limit of the development, enjoyed open aspects to