When an English cartographer must tell a Welsh village that their mountain is only a hill, the offended community sets out to change that. The film is based on a story heard by Christopher Monger from his grandfather about the real village of Taff’s Well in the old county of Glamorgan, and its neighbouring Garth Hill. However, due to 20th century urbanisation of the area, it was filmed in the more rural Llanrhaeadr-ym-Mochnant and Llansilin areas in Powys.