Gandikota is a village and historical fort on the right bank of the Penna river, 15 km from Jammalamadugu in Kadapa district, Andhra Pradesh, India. The fort was the centre of power for various dynasties, such as the Kalyani Chalukyas, Pemmasani Nayakas, and the Golconda Sultanate. Gandikota was the capital of Pemmasani Nayakas for more than 300 years. Pemmasani Ramalinga Nayudu constructed the huge fort at Gandikota with 101 towers replacing the previous sand fort constructed by Kaka Raja, Vassals of Kalyani Chalukya rulers. Various additions of Islamic architecture were made during subsequent Muslim rule. Etymology The fort of Gandikota acquired its name due to the 'gorge', formed between the Erramala range of hills, also known as Gandikota hills and the river Penna (Pennar) that flows at its foot, reducing its width to a mere 100 m (look for the river image in the montage/main image). Geology Gandikota canyon consists of sedimentary rocks, namely 'Gandikota Quartzite' in the Chitravati Group part of Cuddapah Supergroup. The Chitravati Group consists of three formation rank units: the Pulivendla Quartzite; the Tadpatri Formation; and the Gandikota Quartzite. History Early history Gandikota is a village on the right bank of the river Penna, 15 km from Jammalamudugu in Kadapa district, Andhra Pradesh, India. Gandikota area was first identified and made Sand fort in 1123 by Kakatiya Raja of nearby Bommanapalle village and a subordinate of Ahavamalla Someswara I, Kalyani Chalukya ruler. Gandikota came under the rule of Kakatiya dynasty from 1239 A.D to 1304 A.D and ruled by their various subordinates. The village transformed into major fort after the emergence of Pemmasani Nayakas. Recently, Tavva Obul Reddy, a Mydukur-based historian, discovered a copper plate inscription on the history of Gandikonda Fort. The inscription dates back to 16th century. Vemana poet, native of Kadapa district and believed to have lived in Gandikota area for a short period. Jean Baptiste Tavernier visited the fort during his travel to Golconda sultanate. Efforts are being put forth to give Gandikota a world heritage status. Major structures In the fort are two ancient temples, dedicated to Madhava and Ranganatha. They are in ruins and the fort area is full of the debris of ages and many ancient structures in varying stages of decay. The large granary, with a vaulted roof, is now used as watchman's quarters. The Jamia Masjid has two adjacent minarets. A heritage festival is held every year