Step 1: The Sanchi Stupa is one of the oldest stone structures in India, located in Sanchi, Madhya Pradesh, near Bhopal.
Step 2: Built by Emperor Ashoka, it is a significant Buddhist monument and a UNESCO World Heritage Site. The other options refer to stupas located in different regions of India, such as Nagarjunakonda in Andhra Pradesh and Amaravati in the Krishna district.