How did the stupa at Sanchi manage to get preserved despite having hundreds of years of history?

There are several reasons due to which Sanchi stupa managed to survive:

1. The Nawab of Bhopal, Shahjehan Begum and her successor Sultan Jehan Begum allocated a large number of funds for the preservation of the stupa.
2. They funded the museums that were built near the site and also a guesthouse. The activities like the publication of volumes on the site were also funded by them.
3. The stupa was also successful in escaping the eyes of the railway contractors and architectural engineers.
4. The European nations like France and British also showed liberal behaviour and did not carry the excavated objects back to their nation.
5. The preservation of the site was the collective effort of the British and the Nawab of Bhopal.