How many years old is the Sanchi Stupa?

The Sanchi Stupa is from the 3rd century BCE.
On a hilltop near Sanchi Town, Raisen District, State of Madhya Pradesh, India, is the Buddhist complex known as Sanchi, and is known for its Great Stupa. One of India’s oldest stone buildings and a significant piece of Indian architectural history is the Great Stupa in Sanchi. In the third century BCE, Ashoka the Great, the Mauryan emperor, ordered it to be built. Its structure was a straightforward hemispherical brick building built over Buddha relics.