Mustafa Castle is a private-feeling Meerut landmark built by Nawab Mohammad Ishak Khan in memory of his father, the poet and critic Nawab Mustafa Khan Shefta. The appeal is the mix of local history, family memory, and Indo-European architecture rather than a formal museum experience.
It is worth seeking out if you are already exploring Meerut's old cantonment and 19th-century sites. Expect an exterior visit unless access is clearly available when you arrive.