Underground laboratories

Abstract

Underground laboratories provide the low radioactive background environment necessary to explore the highest energy scales that cannot be reached with accelerators, by searching for extremely rare phenomena. To advance the effective-high-energy frontier we need to struggle for background control and reduction. After having discussed the most important characteristics of an underground laboratory, all of the world facilities that are presently operational or in an advanced status of approval are briefly described. None of the projects for very large facilities are described.