The centre of the Milky Way hosts a zoo of high-energy sources, including a supermassive black hole 4 million times heavier than the Sun, the most recent galactic supernova, multiple SNRs, PWNs, and active star-forming regions. It also features a complex interstellar environment with strong magnetic fields and giant molecular cloud complexes that serve as cosmic-scale high-energy particle detectors. The high-energy activity of the Galactic Centre region injects huge amounts of energy into the interstellar medium and in ates bubbles filled with high-energy particles spanning tens of degrees in the sky. CTAO will make a deep exposure of the Galactic Centre region, to find out if it is the black hole that emits gamma-rays, or if the emission comes from a SNR or PWN. It will also make a detailed survey of the region around the Galactic Centre, to trace the locations of injection of energetic particles in the region, understand the mechanism of their diffusion and escape into the outflow powering the Fermi Bubbles and to search for dark matter. In the energy region beyond 500 GeV, synergic work is ongoing between extensive air shower gamma-ray experiments such as LHAASO, HAWC, Tibet ASγ and neutrino telescopes such as IceCube and KM3NeT to observe the secondary gamma-rays and neutrinos from the diffuse ux of cosmic rays wandering millions of years in our galaxy interacting on the interstellar matter and producing them from pion decays. These measurements have the power to drive cosmic-ray composition models and reach a better understanding of their acceleration and propagation to the knee. This work will be supported by CTAO deep surveys to disentangle the contribution of single accelerators along the plane.

H.E.S.S. image of the Galactic Centre (b) after the subtraction of 2 dominant objects (a) with the black hole Sgr A* indicated with a black star. White contours indicate molecular emission tracing gas and cosmic rays illuminating giant molecular clouds and SNRs. [arXiv:0603021].