The edifice known as Firoz Shah's Palace and tahkhana was built by Firoz Shah Tughlaq, the Sultan of Delhi (1351-1388 AD). The palace is built of rubble masonry covered with thick lime plaster. Its arches are supported on sandstone carved pillars possibly belonging to some Hindu temples. The palace complex consists of an open courtyard surrounded by two and three-storied structures. A passage with steps leading to the terrace is embedded in the massive western wall of the palace. This passage was most possibly meant for guarding the roofs of the palace. It has several bastions with hollow cores and has a pillared hall connected with other rooms and cells of the palace. The red sandstone structures on the eastern side of the palace and the lotus tank on the terrace, however, are of much later origin.
The palace, known as Hisar-i-Firuza, located at a strategic point where the old Delhi Multan Road route branched to Khorasan(historic region which lies in northeast of Iran), was built by Firoz Shah Tughlaq in 1354. The construction was completed in 1356. The palace consists of a mosque, a Diwan-e-Aam, a palace for his wife, underground apartments and a granary. The restoration work of the palace started in 1924 and have since been gradually renovated until recent times. The complex has been declared as a Centrally Protected Monument by Archaeological Survey of India.
The artwork in the fort is the synthesis of Islamic architecture and Indian architecture. However, the mosque was built in Seljuk architecture.The palace is built of red sandstone. The material used in the construction of the fort was taken from the destroyed Hindu temples.
The Shahi Darwaza is an east-facing still-standing entrance to the palace, called so because Shahi Darwaza in Persian means royal gate as it was reserved for the royal family. As seen here, this roughly 7 meter tall single-story arched gateway, with small built-in cells inside for the guards on both sides, still serves as the main entrance to the current monument.
The Talagi gate is a west-facing gate with access to ancient Agroha Mound and Sirsa, still-standing facing the current main bus stand of Hisar city. Associated bastions with slanted narrow niches to shoot arrows at attacking enemy armies still exist.
The Nagauri gate was a south-facing now-demolished gate, with access to Nagaur and on to Jodhpur in Rajasthan via Siwani, Jhumpa Khurd, Rajgarh and Churu. It was demolished by the Bansi Lal government to widen the entrance to the market. British Raj had added a tall 2 story clock tower on top of it, now it is all gone but the site is still known as nagori gate.
The Mori gate was an east-facing now-vanished gate where a now-vanished water channel entered the fort complex via a niche (Hindi: mori or hole) in the fort bastion to supply the water. it provided access to Multan (Pakistan) - Kandhar (Afghanistan) - Mashhad (Iran) - Ashgabat (Turkmenistan). The gate is long gone and no sign exists. The location of this used to be the current ramp and road between the fort complex and auto market.
The Delhi gate, located at current Mehta Nagar here near Shaheed Bhagat Singh Chowk, was an east-facing now-vanished gate that was on the path leading to Delhi on Delhi Multan Road. Its location used to be near current Gandhi statue inside the crowded market.