Currently operating resonant-mass gravitational-wave detectors include:

ALLEGRO in Louisiana (United States)

NIOBE in Western australia

AURIGA near Padua in Italy

EXPLORER (an Italian experiment) in Switzerland

NAUTILUS at Frascati in Italy

MiniGRAIL at Leiden in the Netherlands

Although these detectors are all operating independently, any potential detection of a gravitational wave would be checked against the observations of other facilities in order to confirm that it was real and not merely local noise.