English: Chitradurga Fort or as the British called it Chitaldoorg, is a fortification that straddles several hills and a peak overlooking a flat valley in the Chitradurga District, Karnataka, India. The fort's name Chitrakaldurga, which means 'picturesque fort' in Kannada, is the namesake of the town Chitradurga and its administrative district.

The fort was built in stages between the 11th and 13th centuries by the dynastic rulers of the region including the Chalukyas and Hoysalas, later the Nayakas of Chitradurga of the Vijayanagar Empire.The Nayakas of Chitradurga, or Palegar Nayakas, were most responsible for the expansion of the fort between the 15th and 18th centuries.

Chitradurga is formed of two words in the Kannada language: ‘chitra’ means “picture” and ‘durga’ means “fort” and is tagged with the English word ‘fort’ to form the name “Chitradurga Fort”. It is also locally known as “Kallina Kote” or Stone Fortress, which is also formed of two Kannada words ‘Kallina’: “Stone” and Kote:“Fort”. Other names used in Kannada are ‘Ukkina Kote”: “Steel Fort” (metaphorically used to mean an impregnable fort) and ‘Yelusuttina Kote’: “Seven Circles Fort”.

Between 1500 AD and 1800 AD, Chitradurga Fort witnessed a turbulent history starting with the Vijayanagar Empire; the empire had gained control of this region from the Hoysalas. Vijayanagar rulers brought the Nayakas, the traditional local chieftains of the area, under their control as their feudatory, until their dynastic reign ended in 1565 A.D. Thereafter, the Nayakas of Chitradurga took independent control of the region and their clan ruled for more than 200 years until the last of their rulers, Madakari Nayaka V, was defeated by Hyder Ali of Mysore Kingdom, in 1779. During all these years, Chitradurga Fort was central to the reign, particularly of the Nayakas.

Folk legend links the hills surrounding the fort to the epic Mahabharata. It is said that a man-eating giant named Hidimbasura lived on the Chitradurga hill and had terrorized everyone around. When the Pandavas came with their mother Kunti in the course of their exile, Bhima had a duel with Hidimba. Hidimba was slain by Bhima and peace returned to the area. Legend further states that the boulders were part of the arsenal used during that duel.

The Nayak Palegars built the fort as an impregnable fortification for defense purposes with 19 gateways, 38 posterior entrances, 35 secret entrances, four invisible passages, water tanks and 2000 watch towers to guard and keep vigil on the enemy incursions. The storage warehouses, pits and reservoirs were primarily designed to ensure the food, water and military supplies required to endure a long siege. Uniquely, all these facilities are still well conserved.Seven walls (called Yelusuttinakote in local language) form the fort. Each wall has a gate with an ascending access through winding narrow corridors which would make it difficult to use elephants for attacking the fort or to use “battering rams” to break down the gates. Small embrasures in the fort walls were provided for use by archers to shoot arrows at the enemy. Four gates were provided in the outermost walls. The four gates (called Bagilu in Kannada) are Rangayyana Bagilu, Siddayyana Bagilu, Ucchangi Bagilu and Lalkote Bagilu. Among the elaborate gateways, the gateway to the east of the fort has architectural features typical of the Bahmani Sultanate. Depending on the topography and the geological strata of the land, the fort walls were built with height ranging from 5–13 metres (16–43 ft). Initially, it was built in mud but was subsequently strengthened in stretches with granite stone slabs in the 18th century. An outstanding feature noticed in several stretches of the fort walls is that no cementing material was used in joining the large granite cubes that have been neatly sized, cut, trimmed and placed in position. The total length of the fort walls is about 8 kilometres (5.0 mi) and covers an area of about 1,500 acres (610 ha). It is also said that when the upper fort was strengthened for military purposes with gun positions, the services of French mercenaries were used.The massive 'Palace of Stones' fort contained many buildings and many temples set in the rocky surroundings on the hill. Madakari Nayaka V, the last ruler of the Nayakas of Chitradurga, utilized the fort successfully for defense until he was defeated by Hyder Ali in 1779. The fort thus stands as a tribute to the Nayakas who ruled this part of Karnataka.

Subsequent additions to the forts were built with burnt bricks, set in mortar, plastered by a thin layer of cement or lime, and painted. However, the fort now shows deterioration. The mud brick walls of the storehouses and granaries at the fort are getting eroded due to monsoon rains.

Eighteen temples were built in the upper fort. Some of the well known temples were the Hidimbeswara (an ancient legend is linked to it), Sampige Siddeshwara, Ekanathamma, Phalguneshwara, Gopala Krishna, Lord Hanuman, Subbaraya and Nandi.