The Midlothian town of Dalkeith has had an eventful history. Cromwell's officer, General Monck, was Commander in Scotland, and the government of the country was based out of Dalkeith Castle. In the seventeenth century, Dalkeith had one of Scotland's largest markets in its exceptionally broad High Street. In 1831 Dalkeith was linked to Edinburgh by a railway line that transported coal, minerals and agricultural produce. Two decades later, in 1853, a corn exchange, at the time the largest indoor grain market in Scotland, was built, and in 1879 Dalkeith was where Gladstone first started his campaign to become British prime minister. The surrounding villages also have their fair share of historical significance: Newtongrange was Scotland's largest mining village in the 1890s and today houses the National Mining Museum; Bonnyrigg was a mining village until the 1920s; Lasswade was a popular holiday resort in the nineteenth century for wealthy Edinburgh residents; and in nearby Roslin is Rosslyn Chapel, famous for its connections to the Knights Templar and the Holy Grail and which featured in The Da Vinci Code.