During its first years of operation, the H.E.S.S. array of imaging atmospheric Cherenkov telescopes has revealed a sky full of sources of very high energy gamma rays, has demonstrated the great power of the Cherenkov technique, and has motivated work towards a future, even more powerful facility: the Cherenkov Telescope Array CTA. The talk will illustrate some of the key results from H.E.S.S., mention some of the open questions, and present the concept and goals of CTA.