Mae'r cwcis hyn yn gwbl angenrheidiol ar gyfer weithrediad y wefan.
Rydym yn defnyddio Google Analytics i fesur sut ydych yn defnyddio'r wefan er mwyn i ni ei wella yn seiliedig ar angen defnyddwyr.
Gall y cwcis hyn gael eu gosod gan wefannau trydydd parti a gwneud pethau fel mesur sut rydych yn gwylio fideos YouTube.
Amgueddfa Cymru
Photograph captioned 'Blaenavon Ironworks. Side view of the remnants of one of the five blast furnaces with the rounded interior of the furnace just appearing above the external wall. In the wall itself are a number of washers which fitted on the ends of the wrought iron reinforcing bars, features of stone furnaces built early in the 19th century. Across the broken roof of a cast house which abutted the front of the furnace is the shell of a water balance tower standing above the mouth of the coal level.' Mounted on card. Made for the exhibition RECORDING WALES 3 in 1970/1971.