Sanquhar is a town on the River Nith in Dumfries and Galloway, Scotland. It lies north of Thornhill and west of Moffat. It is a former Royal Burgh.Sanquhar is notable for its tiny post office (established in 1712), claimed to be the oldest working post office in the world. It was also the place where the Covenanters, who opposed episcopalisation of the church, signed the Sanquhar Declaration renouncing their allegiance to the King, an event commemorated by a monument in the main street. The church of St. Brides contains a memorial to James Crichton, a 16th-century polymath. The ruins of Sanquhar Castle stand nearby. Nithsdale Wanderers, the local team, were formed in 1897. In 1924–25, Wanderers won the Scottish Division Three.HistoryThe name "Sanquhar" comes from the Scottish Gaelic language Seann Cathair, meaning "old fort". There is a 15th Century castle ruin that overlooks the town, but the name predates even this ancient fort. The antiquary, William Forbes Skene even considered it the probable location of the settlement named Corda in Ptolemy's Geographia. With its location along the River Nith, Sanquhar has been a major crossroads for centuries. Artifacts have been found here from Neolithic times. The remains of several prehistoric British forts can be found in the area as well as traces of a Roman outpost.