The Dhamek Stupa is the most prominent structure in Sarnath, marking the spot where Lord Buddha delivered his first sermon to his five disciples. This massive stupa, built in 500 CE, stands at a height of 43.6 meters and is adorned with intricate carvings that depict flora, humans, and geometric patterns. The stupa's monumental presence and historical significance make it a must-visit site for pilgrims and history enthusiasts alike.