The core activity of Metz + Hunkeler AG encompasses three main areas: 1. **Building Construction**: The company offers services in the field of building construction, which includes planning, construction, and renovation of buildings and structures. 2. **Civil Engineering**: Metz + Hunkeler AG is also active in civil engineering, which includes the construction of infrastructure projects such as roads, bridges, tunnels, and other underground structures. 3. **Dismantling and Demolition**: The third area includes dismantling and demolition, i.e. the disassembly and removal of existing structures, as well as the recycling of building materials. Overall, the core activity of the company can be described as comprehensive construction services in the fields of building construction, civil engineering, and dismantling and demolition.