The Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors are located in which country?

United States
Scientists for the first time have observed ripples in the space-time called gravitational waves. This confirms a major prediction of Albert Einstein’s 1915 general theory of relativity and opens an unprecedented new window onto the cosmos. The gravitational waves were detected by both of the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington, USA.