Geotechnical engineering has been a critical aspect of construction and infrastructure throughout human history, enabling ancient civilizations to develop impressive structures. Their ability to select appropriate sites, to use suitable materials, and to employ innovative construction techniques allowed them to create structures that have not only endured for millennia but continue to inspire modern engineering. One notable example is the use of Mechanically Stabilized Earth (MSE) systems in antiquity, which involved reinforcing soil with various materials to improve strength and stability. While modern MSE systems typically incorporate synthetic materials such as geotextiles, the core principle of soil reinforcement has ancient origins. This study examines several geotechnical structures from antiquity that utilized MSE techniques, showcasing the technological achievements of past civilizations and providing insight into their geotechnical expertise. A particular focus is placed on sections of the Great Wall of China, specifically those constructed during the Han Dynasty, which incorporated a form of soil reinforcement. To assess the effectiveness of these historical MSE systems, computational / numerical models were developed using the Bishop Analysis for slope stability and the Finite Element Stress Analysis Method. Additionally, the study evaluates the structural vulnerability of these constructions in the absence of MSE systems, highlighting their critical role in stability and longevity. The findings from the numerical simulations are presented and discussed, offering valuable perspectives on the contributions of ancient geotechnical engineering practices.