Mela means a fair, and as with all fairs plenty of business is done at Kumbh Melas.

BBC: The magic of India's Kumbh Mela

Both Kumbh Melas I saw were remarkable feats of organisation, occasions when the much-maligned Indian civil servants covered themselves with glory.

BBC: The magic of India's Kumbh Mela

The octogenarian has an impressive record of reuniting people who get lost at the Kumbh Mela - he set up his first camp in 1946 and has covered five Maha Kumbh festivals (which fall once in 12 years), six half-Kumbh and 56 Magh melas that are held every January.

BBC: A day at the Kumbh Mela festival