To address the question of how viral fusion proteins catalyze membrane fusion, we were focusing on the entry mechanism of bunyaviruses by using cutting-edge, high spatial and temporal resolution bio-imaging techniques. Bunyaviruses, and Rift Valley fever virus in particular, were chosen as a model system as they form an emerging viral threat to humans and animals, no approved vaccines or antivirals exist for human use and they were understudied compared to other class II fusion protein systems. Cryo-electron microscopy and tomography were applied to study the structures of virus and virus-like particles, in addition to virus–receptor and virus–membrane complexes. Advanced fluorescence microscopy and spectroscopy techniques were used to probe the dynamics of virus fusion membrane fusion. Our results show how the viral glycoproteins are organised on the surface Rift Valley virus. By mixing virus particles and liposomes, we were able to show how the arrangement of the fusion glycoproteins changes allowing the virus to attack the target membrane by inserting its hydrophopic fusion peptides into it. This step constitutes the first step in the membrane fusion process and proposes a step for intervention of antivirals or antibodies preventing this membrane attack from happening.