Laboratories located underground are characterised by specific geophysical, geothermal, and geological conditions, which are much different to overground laboratories. For instance, the low natural background radiation enables to create an isolated environment suitable for e.g. nuclear industry and applied scientific research. The potential of underground laboratories from the Baltic Sea region, which are often transformed from traditional mining facilities, is still left untapped, offering thriving business and employment opportunities. The laboratories could further be exploited in the fields of mining, tunnel construction, radiation or geophysical background measurement instruments, nuclear sciences, microbiology, or even farming and tourism. 14 partners from eight countries, including six underground laboratories, teamed up in the Interreg BSUIN project to trigger together innovative spirit in the Baltic Sea region.