-One of the pivotal questions in the dynamics of the oceans is related to the cascade of mechanical energy in the abyss and its contribution to mixing. Here, we propose internal wave attractors in the large amplitude regime as a unique self-consistent experimental and numerical setup that models a cascade of triadic interactions transferring energy from large-scale monochromatic input to multi-scale internal wave motion. We also provide signatures of a discrete wave turbulence framework for internal waves. Finally, we show how beyond this regime, we have a clear transition to a regime of small-scale high-vorticity events which induce mixing.Introduction. -The continuous energy input to the ocean interior comes from the interaction of global tides with the bottom topography [1]. The subsequent mechanical energy cascade to small-scale internal-wave motion and mixing is a subject of active debate [2] in view of the important role played by abyssal mixing in existing models of ocean dynamics [3][4][5]. A question remains: how does energy injected through internal waves at large vertical scales [6] induce the mixing of the fluid [2]?In a stratified fluid with an initially constant buoyancy frequency N = [(−g/ρ)(dρ/dz)] 1/2 , where ρ(z) is the density distribution (ρ a reference value) over vertical coordinate z, and g the gravity acceleration, the dispersion relation of internal waves is θ = ± arcsin(Ω). The angle θ is the slope of the wave beam to the horizontal, and Ω the frequency of oscillations non-dimensionalized by N . The dispersion relation requires preservation of the slope of the internal wave beam upon reflection at a rigid boundary. In the case of a sloping boundary, this property gives a purely geometric reason for a strong variation of the width of internal wave beams (focusing or defocusing) upon reflection. Internal wave focusing provides a necessary condition for large shear and overturning, as well as shear and bottom layer instabilities at slopes [7][8][9][10].In a confined fluid domain, focusing usually prevails, leading to a concentration of wave energy on a closed loop, the internal wave attractor [11]. Attractors eventually