The Walferdange Underground Laboratory for Geodynamics (WULG) is located in an gypsum mine (originally exploited by a commercial company). The sedimentary surface layer above the mine is about 80 meters thick with a distance between the entrance and the old laboratory of 800 meters and the temperature is about 13°C at the end of the mine. This is the ideal place to perform very high precision geophysical measurements.The mine has hosted the laboratory since 1967 when the first instruments were installed (gravimeters and pendulums). Since that time, many more instruments for geophysics and seismology purposes have been installed. In 1989, following the later termination of mining activities, the final step towards the “Walferdange Undergroung Laboratory for Geodynamics” (WULG) was completed with extensive public funds.Since then the WULG is open to all interested researchers for geodynamic measurements and instrumental testing and investigations.The advantages of the gypsum mine are: stable temperature; no running water; low anthropogenic noise level; easy to access.