In the seventeenth century, a revolution took place in the world of astronomy, with the invention of the telescope. The first telescope worked with lenses and was developed in Middelburg by Hans Lippershey. But later that century, various astronomers, including Isaac Newton, made reflector telescopes.
Nowadays, all large telescopes work with mirrors. These can be made wider, are less affected by troublesome lens effects and have a stronger lens performance, so the telescope as a whole remains more compact. Space telescopes such as Hubble and the shiny new James Webb Space Telescope also work with mirrors.
If you would like to see a larger telescope in real life, students of astronomical association“L.A.D. Kaiser” organise guided tours in the Old Leiden Observatory. Pay them a visit sometime!