GOV.WALES uses cookies which are essential for the site to work. Non-essential cookies are also used to tailor and improve services. By continuing to use this site, you agree to our use of cookies.
Context: Ystyr “gweithrediadau mwyngloddio” yw cloddio a gweithio mwynau ar dir, boed hynny drwy weithio ar yr arwyneb neu o dan y ddaear, ac mae’n cynnwys [...] echdynnu mwynau o arglawdd rheilffordd nas defnyddir.