Mae Llywodraeth Cymru wedi cyhoeddi bod awdurdodau lleol Cymru wedi cael eu gwahodd i wneud cais i adeiladu un o ddwy ysgol newydd wrth iddi lansio Her Ysgolion Cynaliadwy.
Welsh local authorities have been invited to bid to build two new schools, the Welsh Government has announced, as it launches its Sustainable Schools Challenge.