  Because of its nearness to Earth, the centre of the Milky Way is the only
galaxy nucleus in which we can study the characteristics, distribution,
kinematics, and dynamics of the stars on milli-parsec scales. We have accurate
and precise measurements of the Galactic centre's central black hole,
Sagittarius A*, and can study its interaction with the surrounding nuclear star
cluster in detail. This contribution aims at providing a concise overview of
our current knowledge about the Milky Way's central black hole and nuclear star
cluster, at highlighting the observational challenges and limitations, and at
discussing some of the current key areas of investigation.
