But, to realise their full value, they also need to be kept in good condition and supported by types of ownership that can sustain them for the long term.
Ond, er mwyn manteisio ar eu gwerth yn llawn, mae hefyd angen eu cadw mewn cyflwr da a’u cefnogi â mathau o berchnogaeth sy’n gallu eu cynnal yn yr hirdymor.