On September 14, 2015 the twin LIGO detectors registered triggers that
were later confirmed to be the first direct detection of gravitational
waves and the first observation of a black hole binary. In this talk
we will discuss the nature of gravitational waves, the property of
black holes observed and new strong field tests of gravity we have
been able to do. Future observations could detect more exotic systems
such as precessing binaries and facilitate precision tests of general
relativity.