Turbulent convection into stratified two-layer fluid systems in the presence of rotation has been investigated in a cylindrical laboratory tank. For a wide range of conditions the vertical stability of the flow depends only on the Richardson number Ri = g′h0/(B0R)2/3 (here, g′ = gδ ρi/ρ0 is the jump in the reduced gravity across the density interface, δ ρi is the jump in density itself, h0 is the depth of the top layer, B0 is the surface buoyancy flux and R is the radius of the source). We have found that for values of Ri greater than a critical value of Ric ≈ 11, the convective flow did not penetrate through the density interface, regardless of the values of the convective Rossby number Ro* = (B0/f3h02)1/2 of the flow (here f is the Coriolis parameter). In this case after the convective layer interacted with the density interface the mixed fluid, of intermediate density, propagated radially along the interface in the form of an intrusion. Later, if Ro* was less than approximately 5, mesoscale vortices with mean diameter D ≈ 8(RoR)2/3 and maximum swirl velocity v ≈ (B0R)1/3 were generated at the edge of this propagating front (here RoR = (B0/f3R2)1/2 is the Rossby number based on R). When Ri was less than 11, the convective flow eventually penetrated through the density interface and into the bottom layer. This occurred through the formation of discrete ‘convective holes’ beneath the source. At large values of Ro*, and at early times, one turbulent plume penetrated into the bottom layer from each hole. Later the initial holes coalesced to create one large lesion beneath the source.