King William's College (Colleish Ree Illiam in Manx) is an International Baccalaureate HMC independent school for ages 3 to 18, situated near Castletown on the Isle of Man. The College is located on two sites in Castletown; the senior school occupies a campus which has pride of place on the shore of Castletown Bay, while The Buchan School, the College's preparatory school, is located in the Westhill part of Castletown, some two miles from the main campus. The College, known as KWC or to the local people as King Bill's, was originally for boys only but became co-educational in the 1980s. Today there are roughly five hundred pupils, many of whom are from beyond the British Isles.