Title: Exceptional lensing clusters in recent HST surveys
Abstract: Massive gravitational lensing galaxy clusters have recently been targeted with the Hubble Space Telescope (HST) within the RELICS and BUFFALO surveys. Such observations, with varying strategies regarding depth and area, allow us to detect galaxies which would otherwise be too faint as well as modelling the dark matter distribution in these foreground structures. I will present the main science cases and recent results from these lensing cluster observations.