Rammed earth has been used in construction for thousands of years, with evidence of its use dating as far back as the Neolithic Period. Commonly used especially in China, the technique was applied to both ancient monuments and vernacular architecture, with the Great Wall utilizing the technique. Though interest in rammed earth declined in the 20th century, some continue to advocate its use today, citing its sustainability in comparison to more modern construction methods. Most notably, rammed earth structures use local materials, meaning they have low embodied energy and produce little waste.