Pounding between structures in series during earthquakes may cause serious damage in the structural elements. The aim of this paper is to show the results of an experimental and numerical study that is focused on pounding between more than two structures which may be called "structures in series". In this study, the shaking table experiments, as well as the numerical analyses, were performed using three tower models including rigid and flexible towers with different configurations and different gap distances under several earthquake excitations. The results show that pounding may affect the behaviour of the structures significantly. They also indicate that the rigid towers are more influenced by pounding than the flexible ones. Moreover, increasing or decreasing the gap distance may lead to increase or decrease in the response under different earthquakes with no specific trend. Furthermore, the optimal gap size has been found to be either the distance which prevents pounding or the zero gap. The results of the numerical study clearly indicate that earthquake induced pounding may result in considerable permanent deformation of the inelastic structures which changes the seismic gap distance between the towers resulting in a new gap distance. This new gap distance changes the pattern of the pounding in the series of towers. Moreover, increasing the steel yielding stress changes the pattern of pounding as it decreases the permanent displacement and increases the number of poundings between the adjacent towers