Galaxy clusters magnify the images of distant galaxies which serendipitously lie behind them. This gives us the opportunity to spatially resolve intrinsically faint distant galaxies in a level of detail which would otherwise require the increased light grasp and resolution of the next generation telescopes, still a decade away. In this talk, I will show some recent results which utilize strong gravitational lensing to map the kinematics and distribution of star-formation within galaxies between z=2 and z=5 on scales approaching 100pc using optical, near-infrared and sub-mm facilities.