Congress president Rahul Gandhi on Monday began his two-day tour of politically significant Malwa-Nimar region in the poll-bound Madhya Pradesh by offering prayers at the famous Mahakaleshwar Temple, devoted to Lord Shiva, in Ujjain. Clad in a 'dhoti', he performed 'puja' at the ancient temple, which is one of the 12 'Jyotirlingas' (special shrines dedicated to Lord Shiva) in the country.