Ujjain is a very important pilgrimage for Hindus as it is one of the 12 Jyotirlingas. The city is situated on the bank of the river Kshipra. Kumbh Mela which is also the World's largest religious gathering is held near the Kshipra river once every 12 years. One more important temple is there which is also a Shiv Temple Kal Bhairav holds a importance in Hindu culture. The temple has a beautiful paintings on its wall. Apart from having religious importance, the city holds scientific importance as well. The city has the first meridian of longitude passing from Ujjain and is considered as the Greenwich of the country.