The Ujjain Observatory, also known as the Vedhshala, is the oldest known astronomical observatory in India. It was built in the 5th century BCE and is located in Ujjain, Madhya Pradesh.

Nilakantha Somayaji was an astronomer-mathematician who built the Nilakantha's Observatory in the 15th century CE. The observatory is located in Kerala, India.

Maharaja Jai Singh II built the Jantar Mantar in Jaipur, Rajasthan in the 18th century CE. It is a collection of astronomical instruments that were used to study the movement of celestial bodies.

The main purpose of the Delhi Observatory was to study the movement of celestial bodies. It was built in the 17th century CE and is located in Delhi, India.

The Man Mandir Observatory is located in Varanasi, Uttar Pradesh. It was built in the 16th century CE and is one of the oldest observatories in India.

The Jantar Mantar in Jaipur is the largest astronomical observatory in India. It consists of a collection of 19 astronomical instruments that were used to study the movement of celestial bodies.

The Madras Observatory was built by the British in the 19th century. It is located in Chennai, Tamil Nadu and is one of the oldest observatories in India.

The Great Madras Telescope was the telescope that was used at the Madras Observatory. It was one of the largest telescopes in the world when it was built in the 19th century.

The Kodaikanal Solar Observatory is located in Kodaikanal, Tamil Nadu. It was established in the 19th century and is one of the oldest solar observatories in the world.

The main purpose of the Kodaikanal Solar Observatory is to study the Sun. It is one of the few observatories in the world that is dedicated to the study of the Sun.

The Aryabhatta Research Institute of Observational Sciences is located in Nainital, Uttarakhand. It was established in the 20th century and is one of the leading astronomical research institutes in India.

The Aryabhatta Telescope is located at the Aryabhatta Research Institute of Observational Sciences. It is one of the largest telescopes in India and is used to study a wide range of astronomical objects.

The Indian Astronomical Observatory is located in Hanle, Ladakh. It is one of the highest observatories in the world and is used to study a wide range of astronomical objects.

The main purpose of the Indian Astronomical Observatory is to study the stars. It is one of the few observatories in the world that is dedicated to the study of stars.

The Vainu Bappu Observatory is located in Devasthal, Uttarakhand. It was established in the 20th century and is one of the leading astronomical research institutes in India.