The Qila Mubarak was first developed as a mud fort or Kachi Garhi. Baba Ala Singh constructed the Pacca Qila after his conquest of Sirhind. From the receipts of the octroi on the merchandise passing through his territory of the G.T. road, he constructed the Qila. The present Qila is divided into two parts- one, the Qila Androon, the interior portion, was built by Ala Singh. Situated on a mound, it ascends as one moves into it. While the other i.e., between the Qila Androon and outer walls with the secretariat on the left and Darbar Hall on the right, was built by Maharaja Karam Singh.
The Darbar Hall is now converted into a mini museum where rare arms and armours including a sword of Nadir Shah known as ‘Shikar Gah’ are on display. Most precious pieces of art are the rich collection of tree-like chandeliers made of Bohemian cut-glass emitting prism like radiant splendour and sheen. To those interested in metallurgy and guns, a visit to the Cannon Park within the premises of the Qila Mubarak would certainly be a thrilling experience of life time. The murals inside the palaces are rare specimen of the Kangra and Rajasthan paintings.