On megaparsec scales, matter and galaxies have aggregated into a complex network of interconnected filaments, wall-like structures and compact clusters surrounded by large near-empty void regions. Dubbed the 'Cosmic Web', theoretical and observational studies have led to its recognition as a key aspect of structure in the Universe, representing a universal phase in the gravitationally driven emergence and evolution of cosmic structure. IAU Symposium 308 marked the centenary of the birth of the Russian physicist and cosmologist Yakov B. Zeldovich (1914-87), who was instrumental in the...