Thornhill is a town in the Mid Nithsdale area of Dumfries as well as Galloway, Scotland, south of Sanquhar and north of Dumfries on the primary A76 road. Thornhill beings in the Nithsdale valley with the Carsphairn and also Scaur array to the west and the Lowther hillsides to the eastern. It was initially a small town, intended and built in 1717 on the Queensberry Estate on the road linking Dumfries to Glasgow. The Earl of Queensberry initially called the town 'New Dalgarnock' nevertheless the name did not accomplish preferred authorization. The town is mostly made up a grid pattern with the main street of Drumlanrig Street (the A76), East and also West Morton Streets, New Street, Townhead Street and also Gill Road (the A702). The town is near Drumlanrig Castle, a 17th-century turreted manor once the old Douglas garrison, currently home to the Fight it out of Buccleuch and Queensberry. The grounds contain Tibbers Castle which was founded in the 12th or 13th century. One of the most lately released Census data from 2001 places the population at 1,512 inhabitants.