In ancient India, Ujjain was famous for the study of:

Ujjain in ancient India was renowned as a great centre for the study of astronomy.

Anthropology as a formal discipline did not define Ujjain's ancient fame.

Archaeology is a modern field and was not the basis of its reputation.

Geology likewise was not the study for which the city was known.

Ujjain lay on the reference meridian used by Indian astronomers for calculating time and positions.

Great astronomers and the tradition of observatories later linked the city to Jyotisha.