Securing raw materials and energy, safe disposal of wastes and CO2, developing smarter and larger cities and their infrastructures, all require an increasingly complex and innovative utilisation of the underground resources and space. Whereas problems of the past could be resolved from perspectives of single disciplines, emerging issues of geo-systems engineering in rocks require research and development across disciplines. Increasingly important are demonstrations and experimentation under real-life conditions. Well-managed underground research laboratories are one way to address such needs. In this session, we shall discuss possibilities for establishing an integrated network of underground experimental facilities in different rock environments toward a joint collaborative facility, the European Underground Rock Laboratory (EUROL). Colleagues representing such underground facilities/rock laboratories as well as those interested in using such facilities are encouraged to attend.