2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/99694We review the integrable systems which arise as symmetry reductions of Plebanski's heavenly equations, and their generalisations. We also show that all four-dimensional null Kahler-Einstein (or type N hyper-heavenly) metrics with symmetry can be found from solutions to a variable coefficient generalisation of the dispersionless Kadomtsev-Petviashvili equation.Text of a talk given at the conference on "Mathematical Physics, General Relativity and Cosmology", held in honour of Professor Jerzy Plebanski. To appear in the ProceedingsGeneral Relativity and Quantum CosmologyHigh Energy Physics - TheoryMathematical PhysicsExactly Solvable and Integrable Systemstext