Understanding the factors affecting the ground motion during an earthquake is important to estimate the seismic risk, build a resilient structure and ensuring the safety. The ground motions are strongly influenced by seismic source, propagation path and local site effects. There are several local site effects that have a potential to alter the earthquake ground motion such as site response, near source effects and directivity, topography and basin effects. Hence, presence of massive structures like reservoir, mountains, valleys, rivers, sedimentary basins or complex topography can alter the natural characteristics of the surrounding geological environment, leading to changes in the propagation and amplifying or de-amplifying the seismic waves. Quantifying these uncertainties associated with local site condition and obtaining the reliable ground motion estimates can give deeper insight to the risk analysis. Hence the present study aims at understanding and quantifying the effect of water level fluctuation in reservoirs and its corresponding effects on the ground motions. The study also aims at quantifying the ground motion estimates in the presence of massive structures such as Valles marine and Olympus Mon. The spectral element method is used to simulate the regional ground motion by incorporating all the geological complexities to increase the accuracy of the simulated synthetics. The obtained results are compared for a possible case of amplification of ground motions. The effects of massive structures on ground motion during seismic events can be multifaceted and must be carefully considered in seismic hazard assessment and engineering design.