Cultural heritage has been under pressure from impacts of climate change, yet its conservation and rehabilitation seldom play a role in coastal sustainable development. Two-thirds of the world’s population will live in cities until 2050, and more than one billion will live in coastal areas. New digitalization methods and tools have been applied in architectural, urban and landscape design to raise awareness of coastal communities about climate change adaptation and to protect their cultural heritage. Still, younger people have seldom been involved in the planning process, such as the review of master plans. Geogames, location-based games for public engagement, such as Minecraft, have been applied as an active educational tool for young people. Thus, how can Minecraft support youth engagement in co-designing climate adaptation scenarios for heritage-sensitive sites? We applied Minecraft as a geogame to engage 10–12 years old children to co-design climate adaptation scenarios for the Rogerstown Estuary area in North Dublin, Ireland. Parents also got involved, supporting their children’s design process and reflections on climate change impacts and risks to their local/cultural heritage. Young people showed awareness of environmental issues and community needs. New questions emerged about using Minecraft and other geogames for capacity-building in wider consultation processes, as well as informing urban policy-making for greater conservation and sustainability of heritage-sensitive sites.