As complex global challenges threaten our children's future, there is little international debate that schools must foster education for sustainable development (ESD) by unpacking sustainable development (SD) themes and stimulating (meta)cognitive growth towards higher-order epistemological stances conducive of innovation and transformation. Reform is, however, a different story. In countries like Romania, the traditional system manifests substantial inertia beyond declarative adherence to ESD, while students' voices remain typically unheard and unpromoted. Our study appraises the perspectives of 17-year-old students from both urban and rural NE Romania regarding the perceived sources of SD awareness and knowledge, the SD themes of highest personal significance and how SD should be featured in the school curriculum. From the 496 students participating in our online questionnaire-based survey, we learn that school--and specifically Geography--is the main vehicle for SD knowledge and is held most responsible for achieving ESD. Eradicating poverty, Access to education, Wellbeing and Access to Health care are the SD themes of most interest, much more than Action for climate or Alternative sources of energy. We also identify poorly understood SD themes and discuss the significance of all these results in a national and international context.