Louis-Antoine, Duke of Angoulême (the elder son of Charles X of France, last of the Bourbon kings) and his wife Marie-Thérèse-Charlotte, (the daughter of Louis XVI of France and Marie Antoinette), moved into what is now 22 (then 21) Regent Terrace in 1830. Marie-Caroline de Bourbon-Sicile, duchess de Berry, sister in law of the Duc d'Angoulême, also lived at what is now 12 (then 11) Regent Terrace at that time. Her young son, Henri, the Comte de Chambord, is said to have wept bitterly when his family left for Austria in 1832 as he had become very attached to Scotland. The painter Francis Cadell, one of the Scottish Colourists, lived in 30 Regent Terrace from 1930-1935. The western end of Regent Terrace was closed in 2001 to traffic because of security concerns about the United States Consulate. Playfair was responsible for many of the monumental structures on the summit of the hill, most notably the Scottish National Monument. This monument was intended to be another Parthenon and to commemorate Scottish Soldiers killed in the Napoleonic wars. Construction started in 1826 but work was stopped in 1829 when the building was only partially built due to lack of money. It has never been completed. For many years this failure to complete led to its being nicknamed "Scotland's Disgrace" but this name has waned given the time elapsed since the Napoleonic Wars and it is now accepted for what it is. The Royal High School was built on the southern slopes in 1829, forming a part of Edinburgh's skyline. In the 1840s a tunnel was added through the lower south side of the hill (under the High School) taking tracks eastward from the newly built Waverley Station. The west end of the tunnel was remodelled and a second tunnel built in 1902 by Robert Inglis. "Rock House", which overlooks Waterloo Place at the south-western entrance to the hill, was the home of Robert Adamson who in partnership with David Octavius Hill pioneered the calotype process of photography in Scotland in the 1840s. Many of their subjects were photographed in the house and its garden. At the foot of the southern access steps is a memorial to three 19th-century Scottish singers, John Wilson (1800–1849), John Templeton (1802–1886), and David Kennedy (1825–1886). The monument was sculpted by William Grant Stevenson. Political symbol For a number of years, while the Royal High School was earmarked