Gobindgarh Fort at Amritsar was built by the Bhangi misl as Bhangian da Qila and taken and rebuilt by Ranjit Singh Ji from 1809 as the principal treasury fort of the Sikh state.
It is a bastioned fort of European type with a double wall and a moat, built with the involvement of his French officers, and it held the Lahore darbar's reserve treasure including, at various times, the Koh-i-Noor.
Its commander was Fakir Imamuddin, brother of the foreign minister Fakir Azizuddin, which meant one Muslim family held the foreign office, the city of Lahore and the state's principal treasury.
The British took it in 1849 and it remained a military installation for a hundred and sixty years. It was handed over to the Punjab government in 2006 and opened to the public in 2017 as a heritage site.
It is one of very few substantial Sikh-period military structures in Indian Punjab, and it was inaccessible for the whole of the period in which Punjab's heritage was being lost elsewhere, which is why it survives.
The toshakhana inside it held the state's reserve, and the Darbar Sahib's own valuables were kept there at times. The word is still what a government treasury of gifts is called in both countries, and the building it names here is a vault with a fort built round it.
The Bhangi work on the site was a mud enclosure. What replaced it is brick faced, with a rampart, a ditch and an outer wall on the trace the European officers understood, built to stand against artillery rather than against cavalry, which was a new requirement in Punjab when it went up.
It opened to the public as a heritage site in 2017. What it contains now is a sound and light show and a museum, and the fabric is the most complete Sikh period military architecture anywhere.