Nandi Hills or Nandidurg (Anglicised forms include Nandidrug and Nandydroog) is an ancient hill fortress of southern India, in the Chikkaballapur district of Karnataka state. It is located just 10 km from Chickballapur town and approximately 45 km from the city of Bangalore. The hills are nestled between the neighboring towns of Nandi, Muddenahalli, and Kanivenarayanapura. These are the sites of the upcoming $22 Billion, 12,000 acre BIAL IT Investment Region, Sri Sathya Sai Baba Universities, the Indian Institute of Technology Muddenahalli, and the Visvesvaraya Institute of Advanced Technology. The hills are traditionally held as the origin of the Arkavathy river.

Etymology and Historical Temple

There are many stories about the origin of the name Nandi Hills. During the Chola period, Nandi Hills was called Ananda Giri meaning The Hill of Happiness. Another story is that Yoga Nandeeshwara performed penance here, and so it was named after him. Nandi is also commonly called Nandidurga (Fort) because of the fort build here by the ruler Tippu Sultan. It is also perhaps called Nandi Hills because the hill resembles a sleeping bull (Nandi).

Another theory holds that that the hill gets its name from an ancient, 1200 year old Dravidian style Nandi temple situated on this hill. An ancient lord Shiva and Parvati temple also adorns this hill. The Bhoga Nandeeshwara temple in Nandi village is one of the oldest temples in Karnataka dating back to the ninth century. The temple hewn out of rock consists of two complexes. While the first complex houses three deities, the second complex consists of a huge and majestic kalyani pond. The foundation of the temple was constructed by the Banas of ninth century. The Chola rulers of the 11th century constructed the roof of the temple. The marriage hall was built by the Hoysalas in the thirteenth century and a wall of the second complex was built by the Vijayanagar kings. Beautiful stone carvings are a popular tourist site and are a source of inspiration students of art and architecture.

Tourism

The hills are now a popular tourist spot during summer. The state horticulture department maintains a garden for the tourists. The pressure of tourists on the environment here is great with a considerable problem of litter, noise and physical disturbance. Skanda giri is a nearby tourist place.

Tipu's Drop - the famous place from where Tippu Sultan threw his condemned prisoners to death

Tipu's Summer Palace and Fort - During the Ganga period, the Chikkaballapur chieftains built a fort. Tippu strengthened it further and also build a rest house. This used to be Tippus summer bungalow. It is not open to the general public.

Horse Way - A stone doorway in the fort on the North-eastern side, is believed to have been the horse way for helping soldiers to climb the wall on horse back.

Secret Escape Route - A secret passage on the west, is believed to have helped the Kings to escape during unforeseen attacks.

Temples - there are temples dedicated to Sri Bhoga Narasimha, Sri Ugra Narasimha and Sri Yoga Narasimha and you can see beautiful old temples.

Gavi Veerbhadra Swamy temple: on top of the hill, on the way to the Sultanpet, from Tippus palace, natural formation of huge boulders has been transformed into a magnificent temple.

Children's Playground - The Horticulture department maintains a lovely garden for children to play games like the slides, merry-go-round, swings etc.

Nehru Nilaya - where Jawaharlal Nehru used to stay, now a guest house of the horticulture department of India.

Gandhi House, where the Mahatma himself stayed, is under the management of DPAR (Protocol) Government of Karnataka and is reserved for the stay of important dignitaries.

The Horticulture Department runs a vegetarian restaurant and the Karnataka Tourism Department runs a vegetarian / non-vegetarian restaurant "MAYURA".

Rivers - the rivers Pennar, Palar and Arkavati originate from these hills. Most of the sources have dried up. Amruth Sarovar is a beautiful water lake that brims with lucid water all the year round.

Brahmashram - it is said that Sage Ramakrishna meditated here. Its a cool cave. All Munis in the Ashram used to sit and Smoke Up together on the top of the hill beforing starting off their day and this tradition is followed by today's youngsters.

Muddenahalli-Kanivenarayanapura - the home town of Sir M. Visvesvaraya, the legendary architect of modern Karnataka. Along with Kanivenarayanapura, it is the site of the upcoming Sri Sathya Sai Baba University and College of Medicine, Indian Institute of Technology Muddenahalli, 600 crore Visvesvaraya Institute of Advanced Technology, and a 70 crore "Silk City".

Apart from these, there are other interesting places like Anjaneya temple, Nellikayi Basavanna, Antaragange, Baananthi Bande, Bhoga Nandeeshwara temple etc.