Explanation:

Gwalior Fort  is a hill fort near Gwalior, Madhya Pradesh, central India. The fort has existed at least since the 10th century, and the inscriptions and monuments found within what is now the fort campus indicate that it may have existed as early as the beginning of the 6th century. The fort has been controlled by a number of different rulers in its history.

The present-day fort consists of a defensive structure and two main palaces, Gujari Mahal and Man Mandir, built by Man Singh Tomar (reigned 1486–1516 CE). The Gujari Mahal palace was built for Queen Mrignayani. It is now an archaeological museum. The second oldest record of "zero" in the world was found in a small temple, which is located on the way to the top. The inscription is around 1500 years old.