A multimetric gravity theory will be presented, which is an extension to general relativity featuring N >= 2 metric tensors and a corresponding number of standard model copies. Two aspects of multimetric gravity will be discussed in particular: cosmology and structure formation. A simple cosmological model will be presented which exhibits an accelerating expansion of the universe. It will be shown that the formation of structures within this cosmological background solution leads to the formation of clusters and large, empty voids.