  This work is a brief review of applications of hidden symmetries to black
hole physics. Symmetry is one of the most important concepts of the science. In
physics and mathematics the symmetry allows one to simplify a problem, and
often to make it solvable. According to the Noether theorem symmetries are
responsible for conservation laws. Besides evident (explicit) spacetime
symmetries, responsible for conservation of energy, momentum, and angular
momentum of a system, there also exist what is called hidden symmetries, which
are connected with higher order in momentum integrals of motion. A remarkable
fact is that black holes in four and higher dimensions always possess a set
(`tower') of explicit and hidden symmetries which make the equations of motion
of particles and light completely integrable. The paper gives a general review
of the recently obtained results. The main focus is on understanding why at all
black holes have something (symmetry) to hide.
