Galaxy clusters and their environment

Clusters of galaxies are located at the intersection of cosmic filaments. I will first describe how we have found large extensions around clusters, at optical and/or X-ray wavelengths, suggesting that we are indeed detecting the cosmic web around clusters, and I will discuss some galaxy properties in one of these extended filaments. At the cluster scale, I will then describe our searches for substructures in X-rays and show how X-ray temperature, pressure, entropy and metallicity maps can give informations on the cluster history by comparing them with hydrodynamical simulations. Finally, I will talk about several properties of galaxies in clusters, such as galaxy luminosity functions, brightest cluster galaxies, jellyfish galaxies, and asymmetric galaxies.