Testing General Relativity

The text of a lecture given at the Gran Sasso Summer Institute 2014 is presented. It contains a review of the past and present tests of the General Relativity theory. The essentials of the theory are recalled and the measurable effects are listed and analyzed. The main historical confirmations of General Relativity are described. Then, the present situation is reviewed presenting a number of examples. The opportunities given by astrophysical and astrometric observations are shortly discussed. Coming to terrestrial experiments the attention is specially focused on ringlasers and a dedicated experiment for the Gran Sasso Laboratories, named by the acronym GINGER, is presented. Mention is also made of alternatives to the use of light, such as particle beams and superfluid rings