Castlemount was built in 1876 by Mr W J Adcock for Mr Robert Chignell, to accommodate the school he had originally opened on the site of Dover College. The house was a substantial mansion with many gables, built of red brick with stone embellishments. The main entrance to the property was from Laureston Place. After the house was completed, Mr Chignell had the grounds terraced, with lawns and the perimeter planted with trees, and in a few years the barren hillside assumed a park-like appearance. On certain days during the summer Mr Chignell opened his grounds to the public, and it was the public appreciation of this privilege that suggested the idea of Connaught Park. Mr Chignell eventually left Dover and by 1891 the preparatory school for boys was being run by Reverend Thomas Chirol. In 1911, it was taken over by French monks known as Les Frères des Ecoles Chrétiennes who came to England because of an anti-clerical movement in France and established it as a training centre for teachers. At the outbreak of the First World War the monks left Dover and the house was commandeered by the military for use as barracks. In December 1914 the building had a narrow escape as the first bomb dropped from and aeroplane on the United Kingdom fell barely a yard from the perimeter wall. The monks returned after the war and it was from this time that the ghost stories began. It is said the school was haunted by a ghost known as the Black Monk. The monks left Dover for the last time on the outbreak of the Second WorldWar. In 1940 the RAF took over Castlemount as the HQ for a barrage balloon squadron. After the war the building was taken over by Kent Education Committee and turned into the mixed secondary school which opened in 1948. The school was enlarged in the mid 1960s when much needed additional accommodation was added. In June 1973 the main building (the original 1876 house) was devastated by fire, believed to be arson. The school continued in temporary classrooms on the site and rebuilding was completed in 1977. Castlemount was closed in June 1991, with most pupils transferring to Astor School. Plans for the use of the old school, including the boys and girls grammar schools combining on the site, came to nothing. The buildings were demolished and the site re-developed with houses now known as Monastery Avenue.